diff --git a/.travis.yml b/.travis.yml
index c033e2b..4b95de8 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,9 +1,13 @@
 language: python
 sudo: false
-python: 2.7
-env:
-  - TOX_ENV=py27-django111
-  - TOX_ENV=flake8
+matrix:
+     include:
+        - python: 3.6
+          env: TOX_ENV=py36-django111
+        - python: 3.7
+          env: TOX_ENV=py37-django111
+        - python: 3.7
+          env: TOX_ENV=py37-flake8
 install:
   - pip install tox
 script:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index adbeb8c..a3491e4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,15 +1,15 @@
-x.x.x
+2.0.0
 ------
 
-* Support Django 1.11
-* Dropped support for Django 1.7-1.10
-* Changed the base image in Dockerfile from python:2.7 to python:2.7-stretch
-* Used pipenv to manage requirements
-
+* Upgraded to Python 3
 
 1.2.5
 -----
 
+* Added Django 1.11 support
+* Dropped support for Django 1.7-1.10
+* Changed the base image in Dockerfile from python:2.7 to python:2.7-stretch
+* Used pipenv to manage requirements
 * Removed bare excepts for flake8 ([#89](
 https://github.com/unt-libraries/django-premis-event-service/pull/89))
 
diff --git a/Dockerfile b/Dockerfile
index ddcbb94..8d55560 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,5 +1,5 @@
 # vim: set ft=conf
-FROM python:2.7-stretch
+FROM python:3.7-stretch
 
 RUN echo "US/Central" > /etc/timezone
 RUN dpkg-reconfigure -f noninteractive tzdata
@@ -17,7 +17,7 @@ RUN apt-get update -qq && apt-get install -y mysql-client netcat
 
 RUN pip install -U pip setuptools
 RUN pip install pipenv
-RUN pipenv install --dev --system
+RUN pipenv install --dev --system --deploy --ignore-pipfile
 
 ADD wait-for-mysqld.sh /wait-for-mysqld.sh
 ADD appstart.sh /appstart.sh
diff --git a/Pipfile b/Pipfile
index e41f6b6..d80a08c 100644
--- a/Pipfile
+++ b/Pipfile
@@ -4,19 +4,18 @@ verify_ssl = true
 name = "pypi"
 
 [packages]
-lxml = "~=3.3.0"
-codalib = "==1.0.3"
+lxml = "~=4.2.0"
+codalib = {git='https://github.com/unt-libraries/codalib'}
 sqlparse = "*"
-mysql-python = "*"
-Django = "~=1.11.0"
+mysqlclient = "~=1.3.14"
+Django = "~=1.11.28"
 
 [dev-packages]
 django-debug-toolbar = "<=1.9"
 tox = ">=3.13.0"
 pytest-django = ">=3.2.1"
-mock = "==1.3.0"
 factory-boy = "==2.5.2"
 "flake8" = "*"
 
 [requires]
-python_version = "2.7"
+python_version = "3.7"
diff --git a/Pipfile.lock b/Pipfile.lock
index 9d7866c..5ebe68c 100644
--- a/Pipfile.lock
+++ b/Pipfile.lock
@@ -1,11 +1,11 @@
 {
     "_meta": {
         "hash": {
-            "sha256": "d2920d2d0661484bfaebb1b4f611fd4adb203d22d7c919bbdd6457854829ee60"
+            "sha256": "0dacaafc5ee1961c2eda3d7118d343647a646b4bf87e48de6c8a330870f5a508"
         },
         "pipfile-spec": 6,
         "requires": {
-            "python_version": "2.7"
+            "python_version": "3.7"
         },
         "sources": [
             {
@@ -17,100 +17,113 @@
     },
     "default": {
         "codalib": {
-            "hashes": [
-                "sha256:768908580ea67baa6de60b218f292227ad0023760d12130cf13098f0cb2fe387"
-            ],
-            "index": "pypi",
-            "version": "==1.0.3"
+            "git": "https://github.com/unt-libraries/codalib",
+            "ref": "3c8e30097de74a300f7c503802117361a98e5261"
         },
         "django": {
             "hashes": [
-                "sha256:52a66d7f8b036d02da0a4472359e8be1727424fc1e4b4f5c684ef97de7b569e1",
-                "sha256:c85b8c95366e187ca0581d45a6e508107ca4bd38cb45c24aa09d3572074c523d"
+                "sha256:014e3392058d94f40569206a24523ce254d55ad2f9f46c6550b0fe2e4f94cf3f",
+                "sha256:4200aefb6678019a0acf0005cd14cfce3a5e6b9b90d06145fcdd2e474ad4329c"
             ],
             "index": "pypi",
-            "version": "==1.11.23"
+            "version": "==1.11.29"
         },
         "lxml": {
             "hashes": [
-                "sha256:00f760d13c3e7ef2c297ca99e461b01b08d1cd9980d41562f31459b374a7fde3",
-                "sha256:0b6248141bd9551fed16afc9d34dacaa3b32ef4a854e1df41c58c4c47d06dcfa",
-                "sha256:3ecc3a4cd21a1033f461b340d5e115b955b47d33e57214b6a78d364f0e72e335",
-                "sha256:40434af0a82fa45d8ce34ac2dc7dab014fd0b9c1893499f473cd87cb3944fe38",
-                "sha256:c46a72c529398d34eabd05e12948868d9d958caede12f1a37e86d00efc423c92",
-                "sha256:f5fa7d233224e0a441ca23aeab43476c93e416b34b5ce640ca4d63fcb5bfda0e"
+                "sha256:16cf8bac33ec17049617186d63006ba49da7c5be417042877a49f0ef6d7a195d",
+                "sha256:18f2d8f14cc61e66e8a45f740d15b6fc683c096f733db1f8d0ee15bcac9843de",
+                "sha256:260868f69d14a64dd1de9cf92e133d2f71514d288de4906f109bdf48ca9b756a",
+                "sha256:29b8acd8ecdf772266dbac491f203c71664b0b07ad4309ba2c3bb131306332fc",
+                "sha256:2b05e5e06f8e8c63595472dc887d0d6e0250af754a35ba690f6a6abf2ef85691",
+                "sha256:30d6ec05fb607a5b7345549f642c7c7a5b747b634f6d5e935596b910f243f96f",
+                "sha256:3bf683f0237449ebc1851098f664410e3c99ba3faa8c9cc82c6acfe857df1767",
+                "sha256:3ce5488121eb15513c4b239dadd67f9e7959511bd766aac6be0c35e80274f298",
+                "sha256:48be0c375350a5519bb9474b42a9c0e7ab709fb45f11bfcd33de876791137896",
+                "sha256:49bc343ca3b30cd860845433bb9f62448a54ff87b632175108bacbc5dc63e49e",
+                "sha256:4cc7531e86a43ea66601763c5914c3d3adb297f32e4284957609b90d41825fca",
+                "sha256:4e9822fad564d82035f0b6d701a890444560210f8a8648b8f15850f8fe883cd9",
+                "sha256:51a9a441aefc8c93512bad5efe867d2ff086e7249ce0fc3b47c310644b352936",
+                "sha256:5bbed9efc8aeb69929140f71a30e655bf496b45b766861513960e1b11168d475",
+                "sha256:60a5323b2bc893ca1059d283d6695a172d51cc95a70c25b3e587e1aad5459c38",
+                "sha256:7035d9361f3ceec9ccc1dd3482094d1174580e7e1bf6870b77ea758f7cad15d2",
+                "sha256:76d62cc048bda0ebf476689ad3eb8e65e6827e43a7521be3b163071020667b8c",
+                "sha256:78163b578e6d1836012febaa1865e095ccc7fc826964dd69a2dbfe401618a1f7",
+                "sha256:83b58b2b5904d50de03a47e2f56d24e9da4cf7e3b0d66fb4510b18fca0faf910",
+                "sha256:a07447e46fffa5bb4d7a0af0a6505c8517e9bd197cfd2aec79e499b6e86cde49",
+                "sha256:a17d808b3edca4aaf6b295b5a388c844a0b7f79aca2d79eec5acc1461db739e3",
+                "sha256:a378fd61022cf4d3b492134c3bc48204ac2ff19e0813b23e07c3dd95ae8df0bc",
+                "sha256:aa7d096a44ae3d475c5ed763e24cf302d32462e78b61bba73ce1ad0efb8f522a",
+                "sha256:ade8785c93a985956ba6499d5ea6d0a362e24b4a9ba07dd18920fd67cccf63ea",
+                "sha256:cc039668f91d8af8c4094cfb5a67c7ae733967fdc84c0507fe271db81480d367",
+                "sha256:d89f1ffe98744c4b5c11f00fb843a4e72f68a6279b5e38168167f1b3c0fdd84c",
+                "sha256:e691b6ef6e27437860016bd6c32e481bdc2ed3af03289707a38b9ca422105f40",
+                "sha256:e750da6ac3ca624ae3303df448664012f9b6f9dfbc5d50048ea8a12ce2f8bc29",
+                "sha256:eca305b200549906ea25648463aeb1b3b220b716415183eaa99c998a846936d9",
+                "sha256:f52fe795e08858192eea167290033b5ff24f50f51781cb78d989e8d63cfe73d1"
             ],
             "index": "pypi",
-            "version": "==3.3.6"
+            "version": "==4.2.6"
         },
-        "mysql-python": {
+        "mysqlclient": {
             "hashes": [
-                "sha256:811040b647e5d5686f84db415efd697e6250008b112b6909ba77ac059e140c74"
+                "sha256:062d78953acb23066c0387a8f3bd0ecf946626f599145bb7fd201460e8f773e1",
+                "sha256:3981ae9ce545901a36a8b7aed76ed02960a429f75dc53b7ad77fb2f9ab7cd56b",
+                "sha256:b3591a00c0366de71d65108627899710d9cfb00e575c4d211aa8de59b1f130c9"
             ],
             "index": "pypi",
-            "version": "==1.2.5"
+            "version": "==1.3.14"
         },
         "pytz": {
             "hashes": [
-                "sha256:26c0b32e437e54a18161324a2fca3c4b9846b74a8dccddd843113109e1116b32",
-                "sha256:c894d57500a4cd2d5c71114aaab77dbab5eabd9022308ce5ac9bb93a60a6f0c7"
+                "sha256:1c557d7d0e871de1f5ccd5833f60fb2550652da6be2693c1e02300743d21500d",
+                "sha256:b02c06db6cf09c12dd25137e563b31700d3b80fcc4ad23abb7a315f2789819be"
             ],
-            "version": "==2019.2"
+            "version": "==2019.3"
         },
         "sqlparse": {
             "hashes": [
-                "sha256:40afe6b8d4b1117e7dff5504d7a8ce07d9a1b15aeeade8a2d10f130a834f8177",
-                "sha256:7c3dca29c022744e95b547e867cee89f4fce4373f3549ccd8797d8eb52cdb873"
+                "sha256:022fb9c87b524d1f7862b3037e541f68597a730a8843245c349fc93e1643dc4e",
+                "sha256:e162203737712307dfe78860cc56c8da8a852ab2ee33750e33aeadf38d12c548"
             ],
             "index": "pypi",
-            "version": "==0.3.0"
-        },
-        "tzlocal": {
-            "hashes": [
-                "sha256:11c9f16e0a633b4b60e1eede97d8a46340d042e67b670b290ca526576e039048",
-                "sha256:949b9dd5ba4be17190a80c0268167d7e6c92c62b30026cf9764caf3e308e5590"
-            ],
-            "version": "==2.0.0"
+            "version": "==0.3.1"
         }
     },
     "develop": {
-        "atomicwrites": {
+        "appdirs": {
             "hashes": [
-                "sha256:03472c30eb2c5d1ba9227e4c2ca66ab8287fbfbbda3888aa93dc2e28fc6811b4",
-                "sha256:75a9445bac02d8d058d5e1fe689654ba5a6556a1dfd8ce6ec55a0ed79866cfa6"
+                "sha256:9e5896d1372858f8dd3344faf4e5014d21849c756c8d5701f78f8a103b372d92",
+                "sha256:d8b24664561d0d34ddfaec54636d502d7cea6e29c3eaf68f3df6180863e2166e"
             ],
-            "version": "==1.3.0"
+            "version": "==1.4.3"
         },
-        "attrs": {
+        "asgiref": {
             "hashes": [
-                "sha256:69c0dbf2ed392de1cb5ec704444b08a5ef81680a61cb899dc08127123af36a79",
-                "sha256:f0b870f674851ecbfbbbd364d6b5cbdff9dcedbc7f3f5e18a6891057f21fe399"
+                "sha256:8036f90603c54e93521e5777b2b9a39ba1bad05773fcf2d208f0299d1df58ce5",
+                "sha256:9ca8b952a0a9afa61d30aa6d3d9b570bb3fd6bafcf7ec9e6bed43b936133db1c"
             ],
-            "version": "==19.1.0"
+            "version": "==3.2.7"
         },
-        "configparser": {
+        "attrs": {
             "hashes": [
-                "sha256:45d1272aad6cfd7a8a06cf5c73f2ceb6a190f6acc1fa707e7f82a4c053b28b18",
-                "sha256:bc37850f0cc42a1725a796ef7d92690651bf1af37d744cc63161dac62cabee17"
+                "sha256:08a96c641c3a74e44eb59afb61a24f2cb9f4d7188748e76ba4bb5edfa3cb7d1c",
+                "sha256:f7b7ce16570fe9965acd6d30101a28f62fb4a7f9e926b3bbc9b61f8b04247e72"
             ],
-            "markers": "python_version < '3.2'",
-            "version": "==3.8.1"
+            "version": "==19.3.0"
         },
-        "contextlib2": {
+        "distlib": {
             "hashes": [
-                "sha256:509f9419ee91cdd00ba34443217d5ca51f5a364a404e1dce9e8979cea969ca48",
-                "sha256:f5260a6e679d2ff42ec91ec5252f4eeffdcf21053db9113bd0a8e4d953769c00"
+                "sha256:2e166e231a26b36d6dfe35a48c4464346620f8645ed0ace01ee31822b288de21"
             ],
-            "markers": "python_version < '3'",
-            "version": "==0.5.5"
+            "version": "==0.3.0"
         },
         "django": {
             "hashes": [
-                "sha256:52a66d7f8b036d02da0a4472359e8be1727424fc1e4b4f5c684ef97de7b569e1",
-                "sha256:c85b8c95366e187ca0581d45a6e508107ca4bd38cb45c24aa09d3572074c523d"
+                "sha256:014e3392058d94f40569206a24523ce254d55ad2f9f46c6550b0fe2e4f94cf3f",
+                "sha256:4200aefb6678019a0acf0005cd14cfce3a5e6b9b90d06145fcdd2e474ad4329c"
             ],
             "index": "pypi",
-            "version": "==1.11.23"
+            "version": "==1.11.29"
         },
         "django-debug-toolbar": {
             "hashes": [
@@ -127,16 +140,6 @@
             ],
             "version": "==0.3"
         },
-        "enum34": {
-            "hashes": [
-                "sha256:2d81cbbe0e73112bdfe6ef8576f2238f2ba27dd0d55752a776c41d38b7da2850",
-                "sha256:644837f692e5f550741432dd3f223bbb9852018674981b1664e5dc339387588a",
-                "sha256:6bd0f6ad48ec2aa117d3d141940d484deccda84d4fcd884f5c3d93c23ecd8c79",
-                "sha256:8ad8c4783bf61ded74527bffb48ed9b54166685e4230386a9ed9b1279e2df5b1"
-            ],
-            "markers": "python_version < '3.4'",
-            "version": "==1.1.6"
-        },
         "factory-boy": {
             "hashes": [
                 "sha256:102c8141511443df01d354610d3b268924100654316709b43ac04648b50bf703",
@@ -154,34 +157,19 @@
         },
         "flake8": {
             "hashes": [
-                "sha256:19241c1cbc971b9962473e4438a2ca19749a7dd002dd1a946eaba171b4114548",
-                "sha256:8e9dfa3cecb2400b3738a42c54c3043e821682b9c840b0448c0503f781130696"
+                "sha256:45681a117ecc81e870cbf1262835ae4af5e7a8b08e40b944a8a6e6b895914cfb",
+                "sha256:49356e766643ad15072a789a20915d3c91dc89fd313ccd71802303fd67e4deca"
             ],
             "index": "pypi",
-            "version": "==3.7.8"
-        },
-        "funcsigs": {
-            "hashes": [
-                "sha256:330cc27ccbf7f1e992e69fef78261dc7c6569012cf397db8d3de0234e6c937ca",
-                "sha256:a7bb0f2cf3a3fd1ab2732cb49eba4252c2af4240442415b4abce3b87022a8f50"
-            ],
-            "markers": "python_version < '3.3'",
-            "version": "==1.0.2"
-        },
-        "functools32": {
-            "hashes": [
-                "sha256:89d824aa6c358c421a234d7f9ee0bd75933a67c29588ce50aaa3acdf4d403fa0",
-                "sha256:f6253dfbe0538ad2e387bd8fdfd9293c925d63553f5813c4e587745416501e6d"
-            ],
-            "markers": "python_version < '3.2'",
-            "version": "==3.2.3.post2"
+            "version": "==3.7.9"
         },
         "importlib-metadata": {
             "hashes": [
-                "sha256:23d3d873e008a513952355379d93cbcab874c58f4f034ff657c7a87422fa64e8",
-                "sha256:80d2de76188eabfbfcf27e6a37342c2827801e59c4cc14b0371c56fed43820e3"
+                "sha256:2a688cbaa90e0cc587f1df48bdc97a6eadccdcd9c35fb3f976a09e3b5016d90f",
+                "sha256:34513a8a0c4962bc66d35b359558fd8a5e10cd472d37aec5f66858addef32c1e"
             ],
-            "version": "==0.19"
+            "markers": "python_version < '3.8'",
+            "version": "==1.6.0"
         },
         "mccabe": {
             "hashes": [
@@ -190,58 +178,33 @@
             ],
             "version": "==0.6.1"
         },
-        "mock": {
-            "hashes": [
-                "sha256:1e247dbecc6ce057299eb7ee019ad68314bb93152e81d9a6110d35f4d5eca0f6",
-                "sha256:3f573a18be94de886d1191f27c168427ef693e8dcfcecf95b170577b2eb69cbb"
-            ],
-            "index": "pypi",
-            "version": "==1.3.0"
-        },
         "more-itertools": {
             "hashes": [
-                "sha256:38a936c0a6d98a38bcc2d03fdaaedaba9f412879461dd2ceff8d37564d6522e4",
-                "sha256:c0a5785b1109a6bd7fac76d6837fd1feca158e54e521ccd2ae8bfe393cc9d4fc",
-                "sha256:fe7a7cae1ccb57d33952113ff4fa1bc5f879963600ed74918f1236e212ee50b9"
+                "sha256:5dd8bcf33e5f9513ffa06d5ad33d78f31e1931ac9a18f33d37e77a180d393a7c",
+                "sha256:b1ddb932186d8a6ac451e1d95844b382f55e12686d51ca0c68b6f61f2ab7a507"
             ],
-            "markers": "python_version <= '2.7'",
-            "version": "==5.0.0"
+            "version": "==8.2.0"
         },
         "packaging": {
             "hashes": [
-                "sha256:a7ac867b97fdc07ee80a8058fe4435ccd274ecc3b0ed61d852d7d53055528cf9",
-                "sha256:c491ca87294da7cc01902edbe30a5bc6c4c28172b5138ab4e4aa1b9d7bfaeafe"
-            ],
-            "version": "==19.1"
-        },
-        "pathlib2": {
-            "hashes": [
-                "sha256:2156525d6576d21c4dcaddfa427fae887ef89a7a9de5cbfe0728b3aafa78427e",
-                "sha256:446014523bb9be5c28128c4d2a10ad6bb60769e78bd85658fe44a450674e0ef8"
-            ],
-            "markers": "python_version == '3.4.*' or python_version < '3'",
-            "version": "==2.3.4"
-        },
-        "pbr": {
-            "hashes": [
-                "sha256:56e52299170b9492513c64be44736d27a512fa7e606f21942160b68ce510b4bc",
-                "sha256:9b321c204a88d8ab5082699469f52cc94c5da45c51f114113d01b3d993c24cdf"
+                "sha256:3c292b474fda1671ec57d46d739d072bfd495a4f51ad01a055121d81e952b7a3",
+                "sha256:82f77b9bee21c1bafbf35a84905d604d5d1223801d639cf3ed140bd651c08752"
             ],
-            "version": "==5.4.2"
+            "version": "==20.3"
         },
         "pluggy": {
             "hashes": [
-                "sha256:0825a152ac059776623854c1543d65a4ad408eb3d33ee114dff91e57ec6ae6fc",
-                "sha256:b9817417e95936bf75d85d3f8767f7df6cdde751fc40aed3bb3074cbcb77757c"
+                "sha256:15b2acde666561e1298d71b523007ed7364de07029219b604cf808bfa1c765b0",
+                "sha256:966c145cd83c96502c3c3868f50408687b38434af77734af1e9ca461a4081d2d"
             ],
-            "version": "==0.12.0"
+            "version": "==0.13.1"
         },
         "py": {
             "hashes": [
-                "sha256:64f65755aee5b381cea27766a3a147c3f15b9b6b9ac88676de66ba2ae36793fa",
-                "sha256:dc639b046a6e2cff5bbe40194ad65936d6ba360b52b3c3fe1d08a82dd50b5e53"
+                "sha256:5e27081401262157467ad6e7f851b7aa402c5852dbcb3dae06768434de5752aa",
+                "sha256:c20fdd83a5dbc0af9efd622bee9a5564e278f6380fffcacc43ba6f43db2813b0"
             ],
-            "version": "==1.8.0"
+            "version": "==1.8.1"
         },
         "pycodestyle": {
             "hashes": [
@@ -259,64 +222,47 @@
         },
         "pyparsing": {
             "hashes": [
-                "sha256:6f98a7b9397e206d78cc01df10131398f1c8b8510a2f4d97d9abd82e1aacdd80",
-                "sha256:d9338df12903bbf5d65a0e4e87c2161968b10d2e489652bb47001d82a9b028b4"
+                "sha256:c203ec8783bf771a155b207279b9bccb8dea02d8f0c9e5f8ead507bc3246ecc1",
+                "sha256:ef9d7589ef3c200abe66653d3f1ab1033c3c419ae9b9bdb1240a85b024efc88b"
             ],
-            "version": "==2.4.2"
+            "version": "==2.4.7"
         },
         "pytest": {
             "hashes": [
-                "sha256:8fc39199bdda3d9d025d3b1f4eb99a192c20828030ea7c9a0d2840721de7d347",
-                "sha256:d100a02770f665f5dcf7e3f08202db29857fee6d15f34c942be0a511f39814f0"
+                "sha256:0e5b30f5cb04e887b91b1ee519fa3d89049595f428c1db76e73bd7f17b09b172",
+                "sha256:84dde37075b8805f3d1f392cc47e38a0e59518fb46a431cfdaf7cf1ce805f970"
             ],
-            "version": "==4.6.5"
+            "version": "==5.4.1"
         },
         "pytest-django": {
             "hashes": [
-                "sha256:264fb4c506db5d48a6364c311a0b00b7b48a52715bad8839b2d8bee9b99ed6bb",
-                "sha256:4adfe5fb3ed47f0ba55506dd3daf688b1f74d5e69148c10ad2dd2f79f40c0d62"
+                "sha256:64f99d565dd9497af412fcab2989fe40982c1282d4118ff422b407f3f7275ca5",
+                "sha256:664e5f42242e5e182519388f01b9f25d824a9feb7cd17d8f863c8d776f38baf9"
             ],
             "index": "pypi",
-            "version": "==3.5.1"
+            "version": "==3.9.0"
         },
         "pytz": {
             "hashes": [
-                "sha256:26c0b32e437e54a18161324a2fca3c4b9846b74a8dccddd843113109e1116b32",
-                "sha256:c894d57500a4cd2d5c71114aaab77dbab5eabd9022308ce5ac9bb93a60a6f0c7"
-            ],
-            "version": "==2019.2"
-        },
-        "scandir": {
-            "hashes": [
-                "sha256:2586c94e907d99617887daed6c1d102b5ca28f1085f90446554abf1faf73123e",
-                "sha256:2ae41f43797ca0c11591c0c35f2f5875fa99f8797cb1a1fd440497ec0ae4b022",
-                "sha256:2b8e3888b11abb2217a32af0766bc06b65cc4a928d8727828ee68af5a967fa6f",
-                "sha256:2c712840c2e2ee8dfaf36034080108d30060d759c7b73a01a52251cc8989f11f",
-                "sha256:4d4631f6062e658e9007ab3149a9b914f3548cb38bfb021c64f39a025ce578ae",
-                "sha256:67f15b6f83e6507fdc6fca22fedf6ef8b334b399ca27c6b568cbfaa82a364173",
-                "sha256:7d2d7a06a252764061a020407b997dd036f7bd6a175a5ba2b345f0a357f0b3f4",
-                "sha256:8c5922863e44ffc00c5c693190648daa6d15e7c1207ed02d6f46a8dcc2869d32",
-                "sha256:92c85ac42f41ffdc35b6da57ed991575bdbe69db895507af88b9f499b701c188",
-                "sha256:b24086f2375c4a094a6b51e78b4cf7ca16c721dcee2eddd7aa6494b42d6d519d",
-                "sha256:cb925555f43060a1745d0a321cca94bcea927c50114b623d73179189a4e100ac"
+                "sha256:1c557d7d0e871de1f5ccd5833f60fb2550652da6be2693c1e02300743d21500d",
+                "sha256:b02c06db6cf09c12dd25137e563b31700d3b80fcc4ad23abb7a315f2789819be"
             ],
-            "markers": "python_version < '3.5'",
-            "version": "==1.10.0"
+            "version": "==2019.3"
         },
         "six": {
             "hashes": [
-                "sha256:3350809f0555b11f552448330d0b52d5f24c91a322ea4a15ef22629740f3761c",
-                "sha256:d16a0141ec1a18405cd4ce8b4613101da75da0e9a7aec5bdd4fa804d0e0eba73"
+                "sha256:236bdbdce46e6e6a3d61a337c0f8b763ca1e8717c03b369e87a7ec7ce1319c0a",
+                "sha256:8f3cd2e254d8f793e7f3d6d9df77b92252b52637291d0f0da013c76ea2724b6c"
             ],
-            "version": "==1.12.0"
+            "version": "==1.14.0"
         },
         "sqlparse": {
             "hashes": [
-                "sha256:40afe6b8d4b1117e7dff5504d7a8ce07d9a1b15aeeade8a2d10f130a834f8177",
-                "sha256:7c3dca29c022744e95b547e867cee89f4fce4373f3549ccd8797d8eb52cdb873"
+                "sha256:022fb9c87b524d1f7862b3037e541f68597a730a8843245c349fc93e1643dc4e",
+                "sha256:e162203737712307dfe78860cc56c8da8a852ab2ee33750e33aeadf38d12c548"
             ],
             "index": "pypi",
-            "version": "==0.3.0"
+            "version": "==0.3.1"
         },
         "toml": {
             "hashes": [
@@ -327,41 +273,32 @@
         },
         "tox": {
             "hashes": [
-                "sha256:dab0b0160dd187b654fc33d690ee1d7bf328bd5b8dc6ef3bb3cc468969c659ba",
-                "sha256:ee35ffce74933a6c6ac10c9a0182e41763140a5a5070e21b114feca56eaccdcd"
+                "sha256:a4a6689045d93c208d77230853b28058b7513f5123647b67bf012f82fa168303",
+                "sha256:b2c4b91c975ea5c11463d9ca00bebf82654439c5df0f614807b9bdec62cc9471"
             ],
             "index": "pypi",
-            "version": "==3.13.2"
-        },
-        "typing": {
-            "hashes": [
-                "sha256:91dfe6f3f706ee8cc32d38edbbf304e9b7583fb37108fef38229617f8b3eba23",
-                "sha256:c8cabb5ab8945cd2f54917be357d134db9cc1eb039e59d1606dc1e60cb1d9d36",
-                "sha256:f38d83c5a7a7086543a0f649564d661859c5146a85775ab90c0d2f93ffaa9714"
-            ],
-            "markers": "python_version < '3.5'",
-            "version": "==3.7.4.1"
+            "version": "==3.14.6"
         },
         "virtualenv": {
             "hashes": [
-                "sha256:94a6898293d07f84a98add34c4df900f8ec64a570292279f6d91c781d37fd305",
-                "sha256:f6fc312c031f2d2344f885de114f1cb029dfcffd26aa6e57d2ee2296935c4e7d"
+                "sha256:00cfe8605fb97f5a59d52baab78e6070e72c12ca64f51151695407cc0eb8a431",
+                "sha256:c8364ec469084046c779c9a11ae6340094e8a0bf1d844330fc55c1cefe67c172"
             ],
-            "version": "==16.7.4"
+            "version": "==20.0.17"
         },
         "wcwidth": {
             "hashes": [
-                "sha256:3df37372226d6e63e1b1e1eda15c594bca98a22d33a23832a90998faa96bc65e",
-                "sha256:f4ebe71925af7b40a864553f761ed559b43544f8f71746c2d756c7fe788ade7c"
+                "sha256:cafe2186b3c009a04067022ce1dcd79cb38d8d65ee4f4791b8888d6599d1bbe1",
+                "sha256:ee73862862a156bf77ff92b09034fc4825dd3af9cf81bc5b360668d425f3c5f1"
             ],
-            "version": "==0.1.7"
+            "version": "==0.1.9"
         },
         "zipp": {
             "hashes": [
-                "sha256:3718b1cbcd963c7d4c5511a8240812904164b7f381b647143a89d3b98f9bcd8e",
-                "sha256:f06903e9f1f43b12d371004b4ac7b06ab39a44adc747266928ae6debfa7b3335"
+                "sha256:aa36550ff0c0b7ef7fa639055d797116ee891440eac1a56f378e2d3179e0320b",
+                "sha256:c599e4d75c98f6798c509911d08a22e6c021d074469042177c8c86fb92eefd96"
             ],
-            "version": "==0.6.0"
+            "version": "==3.1.0"
         }
     }
 }
diff --git a/README.rst b/README.rst
index eca365f..a0b734d 100644
--- a/README.rst
+++ b/README.rst
@@ -19,7 +19,7 @@ due to its widespread use in the digital libraries world.
 Dependencies
 ------------
 
-* Python 2.7+ (not Python 3)
+* Python 3
 * Django 1.11
 * lxml (requires libxml2-dev to be installed on your system)
 * pipenv
@@ -92,16 +92,11 @@ Install the requirements using pipenv_
 
 .. code-block :: sh
 
-    $ pipenv --python 2.7 # (to create the virtualenv)
+    $ pipenv --python 3.7 # (to create the virtualenv)
     $ pipenv install --dev
     $ pipenv shell # (to enter the virtualenv)
     $ exit # (to leave the virtualenv)
 
-If you're using OS X Sierra or later, you will need to specify 2.7.15, because
-a change in Mac handling of OpenSSL broke pip for earlier versions of Python.
-(This will show up as an error saying you have the wrong version of TLS when
-you try to use pip/pipenv.)
-
 If you need to generate a requirements.txt file, you can do so with
 ``pipenv lock -r > requirements.txt``.
 
diff --git a/docs/source/installation.rst b/docs/source/installation.rst
index 57713a9..4869e6c 100644
--- a/docs/source/installation.rst
+++ b/docs/source/installation.rst
@@ -12,7 +12,7 @@ We'll elaborate a bit in this section.
 Dependencies
 ============
 
-- Python 2.7.x
+- Python 3.7.x
 - Django 1.11
 - libxml2-dev libxslt-dev
 - Django Admin - ``django.contrib.admin``
@@ -32,7 +32,7 @@ Install
 
 1. Install the package. ::
 
-    $ pip install git+https://github.com/unt-libraries/django-premis-event-service@1.2.5
+    $ pip install git+https://github.com/unt-libraries/django-premis-event-service
     $ # check https://github.com/unt-libraries/django-premis-event-service/releases for the latest release
 
 2. Add ``premis_event_service`` to your ``INSTALLED_APPS``. Be sure to add ``django.contrib.admin`` if it is not already present. ::
diff --git a/premis_event_service/migrations/0001_initial.py b/premis_event_service/migrations/0001_initial.py
index 7453883..69c331e 100644
--- a/premis_event_service/migrations/0001_initial.py
+++ b/premis_event_service/migrations/0001_initial.py
@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*-
-from __future__ import unicode_literals
+
 
 from django.db import migrations, models
 
diff --git a/premis_event_service/migrations/0002_add_event_ordinal.py b/premis_event_service/migrations/0002_add_event_ordinal.py
index 1c7629f..fa2749a 100644
--- a/premis_event_service/migrations/0002_add_event_ordinal.py
+++ b/premis_event_service/migrations/0002_add_event_ordinal.py
@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*-
-from __future__ import unicode_literals
+
 
 from django.db import migrations, models
 
@@ -144,7 +144,7 @@ class Migration(migrations.Migration):
                 name='event_identifier',
                 field=models.CharField(
                     help_text=(
-                        b'Unique identifier for an event. '
+                        'Unique identifier for an event. '
                         'example: urn:uuid:12345678-1234-5678-1234-567812345678'
                     ),
                     unique=True,
diff --git a/premis_event_service/migrations/0003_auto_20190820_1755.py b/premis_event_service/migrations/0003_auto_20190820_1755.py
index b2abed6..a91f2fd 100644
--- a/premis_event_service/migrations/0003_auto_20190820_1755.py
+++ b/premis_event_service/migrations/0003_auto_20190820_1755.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 # Generated by Django 1.9.13 on 2019-08-20 17:55
-from __future__ import unicode_literals
+
 
 from django.db import migrations, models
 
diff --git a/premis_event_service/migrations/0004_auto_20191008_1646.py b/premis_event_service/migrations/0004_auto_20191008_1646.py
new file mode 100644
index 0000000..2e5911c
--- /dev/null
+++ b/premis_event_service/migrations/0004_auto_20191008_1646.py
@@ -0,0 +1,100 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.25 on 2019-10-08 16:46
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('premis_event_service', '0003_auto_20190820_1755'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='agent',
+            name='agent_identifier',
+            field=models.CharField(db_index=True, help_text='Short identifier for agent to be used in url.', max_length=255, unique=True),
+        ),
+        migrations.AlterField(
+            model_name='agent',
+            name='agent_name',
+            field=models.CharField(help_text='Name of agent.', max_length=255),
+        ),
+        migrations.AlterField(
+            model_name='agent',
+            name='agent_note',
+            field=models.TextField(blank=True, help_text='Optional note about agent.'),
+        ),
+        migrations.AlterField(
+            model_name='agent',
+            name='agent_type',
+            field=models.CharField(choices=[('Personal', 'Personal'), ('Organization', 'Organization'), ('Event', 'Event'), ('Software', 'Software')], help_text='A high-level characterization of the type of agent.', max_length=13),
+        ),
+        migrations.AlterField(
+            model_name='event',
+            name='event_added',
+            field=models.DateTimeField(auto_now=True, db_index=True, help_text='Date/Time event was added to system.'),
+        ),
+        migrations.AlterField(
+            model_name='event',
+            name='event_date_time',
+            field=models.DateTimeField(db_index=True, help_text='Date/Time event was completed.'),
+        ),
+        migrations.AlterField(
+            model_name='event',
+            name='event_detail',
+            field=models.TextField(blank=True, help_text='Additional information about the event.'),
+        ),
+        migrations.AlterField(
+            model_name='event',
+            name='event_identifier_type',
+            field=models.CharField(help_text='The categorization of the nature of the identifier used.', max_length=255),
+        ),
+        migrations.AlterField(
+            model_name='event',
+            name='event_outcome',
+            field=models.CharField(db_index=True, help_text='A categorization of the overall result of the event in terms of success, partial success, or failure.', max_length=255),
+        ),
+        migrations.AlterField(
+            model_name='event',
+            name='event_outcome_detail',
+            field=models.TextField(blank=True, help_text='A non-coded detailed description of the result of the event.'),
+        ),
+        migrations.AlterField(
+            model_name='event',
+            name='event_type',
+            field=models.CharField(db_index=True, help_text='A categorization of the nature of the event use controlled vocabulary.', max_length=255),
+        ),
+        migrations.AlterField(
+            model_name='event',
+            name='linking_agent_identifier_type',
+            field=models.CharField(help_text='A designation of the domain in which the linking agent identifier is unique.', max_length=255),
+        ),
+        migrations.AlterField(
+            model_name='event',
+            name='linking_agent_identifier_value',
+            field=models.CharField(db_index=True, help_text='The value of the linking agent identifier.', max_length=255),
+        ),
+        migrations.AlterField(
+            model_name='event',
+            name='linking_agent_role',
+            field=models.CharField(help_text='The role of the agent in relation to this event.', max_length=255),
+        ),
+        migrations.AlterField(
+            model_name='linkobject',
+            name='object_identifier',
+            field=models.CharField(help_text='Unique identifier for this object.', max_length=255, primary_key=True, serialize=False),
+        ),
+        migrations.AlterField(
+            model_name='linkobject',
+            name='object_role',
+            field=models.CharField(help_text='A high-level characterization of the role of the object.', max_length=255, null=True),
+        ),
+        migrations.AlterField(
+            model_name='linkobject',
+            name='object_type',
+            field=models.CharField(help_text='High-level characterization of the type of object             identifier.', max_length=255),
+        ),
+    ]
diff --git a/premis_event_service/models.py b/premis_event_service/models.py
index 029de4c..bcb26b4 100644
--- a/premis_event_service/models.py
+++ b/premis_event_service/models.py
@@ -36,7 +36,7 @@ class Agent(models.Model):
         help_text="Optional note about agent."
     )
 
-    def __unicode__(self):
+    def __str__(self):
         return self.agent_name
 
     def get_absolute_url(self):
@@ -67,7 +67,7 @@ class LinkObject(models.Model):
         null=True
     )
 
-    def __unicode__(self):
+    def __str__(self):
         return self.object_identifier
 
 
@@ -121,7 +121,7 @@ def search(self, **kwargs):
     def searchunfilt(self, max_ordinal=None):
         if not max_ordinal:
             max_ordinal = self.get_queryset().all().aggregate(models.Max('ordinal'))
-            max_ordinal = max_ordinal.values()[0]
+            max_ordinal = list(max_ordinal.values())[0]
             if max_ordinal:
                 max_ordinal += 1
             # This should never happen in practice. But with test factories, etc.,
@@ -212,7 +212,7 @@ class Event(models.Model):
         through_fields=('event_id', 'linkobject_id')
     )
 
-    def __unicode__(self):
+    def __str__(self):
         return self.event_identifier
 
     class Meta:
diff --git a/premis_event_service/presentation.py b/premis_event_service/presentation.py
index 0315cd8..0ac81c3 100644
--- a/premis_event_service/presentation.py
+++ b/premis_event_service/presentation.py
@@ -1,6 +1,6 @@
 from datetime import datetime
 import uuid
-from urlparse import urlparse
+from urllib.parse import urlparse
 
 from lxml import etree
 from django.shortcuts import get_object_or_404
@@ -72,7 +72,7 @@ def premisEventXMLToObject(eventXML):
     try:
         Event.objects.get(event_identifier=newEventObject.event_identifier)
         raise DuplicateEventError(newEventObject.event_identifier)
-    except Event.DoesNotExist as e:
+    except Event.DoesNotExist:
         pass
     except DuplicateEventError as e:
         raise e
@@ -131,25 +131,25 @@ def premisAgentXMLToObject(agentXML):
             namespaces=PREMIS_NSMAP
         )[0].text.strip()
         agent_object.agent_identifier = agent_identifier
-    except Exception, e:
+    except Exception as e:
         raise Exception("Unable to set 'agent_identifier' attribute: %s" % e)
     try:
         agent_object.agent_name = agent_root.xpath(
             "//premis:agentName", namespaces=PREMIS_NSMAP
         )[0].text.strip()
-    except Exception, e:
+    except Exception as e:
         raise Exception("Unable to set 'agent_name' attribute: %s" % e)
     try:
         agent_object.agent_type = agent_root.xpath(
             "//premis:agentType", namespaces=PREMIS_NSMAP
         )[0].text.strip()
-    except Exception, e:
+    except Exception as e:
         raise Exception("Unable to set 'agent_type' attribute: %s" % e)
     try:
         agent_object.agent_note = agent_root.xpath(
                 "//premis:agentNote", namespaces=PREMIS_NSMAP
         )[0].text.strip()
-    except Exception, e:
+    except Exception:
         pass
     return agent_object
 
@@ -211,7 +211,7 @@ def objectToPremisEventXML(eventObject):
     """
 
     eventXML = etree.Element("%sevent" % PREMIS, nsmap=PREMIS_NSMAP)
-    for fieldName, chain in translateDict.iteritems():
+    for fieldName, chain in translateDict.items():
         if not hasattr(eventObject, fieldName):
             continue
         baseName = chain[0]
diff --git a/premis_event_service/views.py b/premis_event_service/views.py
index b6817d6..04b9990 100644
--- a/premis_event_service/views.py
+++ b/premis_event_service/views.py
@@ -2,7 +2,7 @@
 import math
 from datetime import datetime
 import json
-import urllib
+import urllib.parse
 
 from lxml import etree
 from django.conf import settings
@@ -24,12 +24,12 @@
                            premisAgentXMLgetObject, objectToPremisEventXML,
                            objectToPremisAgentXML, objectToAgentXML,
                            DuplicateEventError, PREMIS_NSMAP, xpath_map)
-from settings import ARK_NAAN
+from .settings import ARK_NAAN
 
 ARK_ID_REGEX = re.compile(r'ark:/'+str(ARK_NAAN)+r'/\w.*')
 MAINTENANCE_MSG = settings.MAINTENANCE_MSG
 EVENT_UPDATE_TRANSLATION_DICT = xpath_map
-XML_HEADER = "<?xml version=\"1.0\"?>\n%s"
+XML_HEADER = b"<?xml version=\"1.0\"?>\n%s"
 
 EVENT_SEARCH_PER_PAGE = 200
 
@@ -126,14 +126,14 @@ def get_page_offsets(query_set, page, page_range, page_lims, per_page=20):
         ordinals = [evt.ordinal for ei, evt in enumerate(offset_qs) if ei and not ei % per_page]
         ordinals = ordinals[::-1]
     offsets_lo = [p for p in page_range if p < page]
-    offsets_lo = zip(offsets_lo, ordinals)
+    offsets_lo = list(zip(offsets_lo, ordinals))
     limit = (pN-page+1) * per_page if pN > page else 1
     ordinals = []
     if limit:
         offset_qs = query_set.filter(ordinal__lte=page_max_ord).order_by('-ordinal')[0:limit]
         ordinals = [evt.ordinal for ei, evt in enumerate(offset_qs) if not ei % per_page]
     offsets_hi = [p for p in page_range if p >= page]
-    offsets_hi = zip(offsets_hi, ordinals)
+    offsets_hi = list(zip(offsets_hi, ordinals))
     return tuple(offsets_lo+offsets_hi)
 
 
@@ -255,7 +255,7 @@ def json_event_search(request):
                 'href': "http://%s%s?%s" % (
                     request.META.get('HTTP_HOST'),
                     request.path,
-                    urllib.urlencode(args_cur)
+                    urllib.parse.urlencode(args_cur)
                 )
             },
             {
@@ -263,7 +263,7 @@ def json_event_search(request):
                 'href': "http://%s%s?%s" % (
                     request.META.get('HTTP_HOST'),
                     request.path,
-                    urllib.urlencode(args_first)
+                    urllib.parse.urlencode(args_first)
                 )
             },
             {
@@ -271,7 +271,7 @@ def json_event_search(request):
                 'href': "http://%s%s?%s" % (
                     request.META.get('HTTP_HOST'),
                     request.path,
-                    urllib.urlencode(args_last)
+                    urllib.parse.urlencode(args_last)
                 )
             },
         ]
@@ -285,7 +285,7 @@ def json_event_search(request):
                 'href': "http://%s%s?%s" % (
                     request.META.get('HTTP_HOST'),
                     request.path,
-                    urllib.urlencode(args)
+                    urllib.parse.urlencode(args)
                 )
             },
         )
@@ -298,7 +298,7 @@ def json_event_search(request):
                 'href': "http://%s%s?%s" % (
                     request.META.get('HTTP_HOST'),
                     request.path,
-                    urllib.urlencode(args)
+                    urllib.parse.urlencode(args)
                 )
             },
         )
@@ -507,7 +507,7 @@ def app_event(request, identifier=None):
             )
         except DuplicateEventError as e:
             return HttpResponse(
-                "An event with id='{}' exists.".format(e.message),
+                "An event with id='{}' exists.".format(e),
                 status=409, content_type="text/plain"
             )
         if type(newEvent) == HttpResponse:
diff --git a/setup.py b/setup.py
index bc37cbf..ebe2b71 100755
--- a/setup.py
+++ b/setup.py
@@ -9,12 +9,14 @@
 
 install_requires = [
     'lxml >= 3.0.0',
-    'codalib>=1.0.1'
+    'codalib'
 ]
 
+dependency_links = ['codalib @ git+https://github.com/unt-libraries/codalib']
+
 setup(
     name="django-premis-event-service",
-    version="1.2.5",
+    version="2.0.0",
     packages=find_packages(exclude=["tests", ]),
     include_package_data=True,
     license="BSD",
@@ -32,8 +34,8 @@
         "Natural Language :: English",
         "Operating System :: OS Independent",
         "Programming Language :: Python",
-        "Programming Language :: Python :: 2.6",
-        "Programming Language :: Python :: 2.7",
+        "Programming Language :: Python :: 3.6",
+        "Programming Language :: Python :: 3.7",
         "Topic :: Internet :: WWW/HTTP :: WSGI :: Application",
     ],
 )
diff --git a/tests/test_models.py b/tests/test_models.py
index 6d707cb..333b2ad 100644
--- a/tests/test_models.py
+++ b/tests/test_models.py
@@ -7,9 +7,9 @@
 
 class TestAgent:
 
-    def test_unicode(self):
+    def test_str(self):
         agent = factories.AgentFactory.build()
-        assert agent.agent_name == unicode(agent)
+        assert agent.agent_name == str(agent)
 
     def test_get_absolute_url(self):
         agent = factories.AgentFactory.build()
@@ -19,16 +19,16 @@ def test_get_absolute_url(self):
 
 class TestLinkObject:
 
-    def test_unicode(self):
+    def test_str(self):
         link_object = factories.LinkObjectFactory.build()
-        assert link_object.object_identifier == unicode(link_object)
+        assert link_object.object_identifier == str(link_object)
 
 
 class TestEvent:
 
-    def test_unicode(self):
+    def test_str(self):
         event = factories.EventFactory.build()
-        assert event.event_identifier == unicode(event)
+        assert event.event_identifier == str(event)
 
     @pytest.mark.django_db
     def test_link_objects_string_with_link_objects(self):
diff --git a/tests/test_presentation.py b/tests/test_presentation.py
index ae76688..a403537 100644
--- a/tests/test_presentation.py
+++ b/tests/test_presentation.py
@@ -1,6 +1,6 @@
 from datetime import datetime
 
-from mock import patch
+from unittest.mock import patch
 from lxml import etree, objectify
 import pytest
 
@@ -41,7 +41,7 @@ def test_validate_event_fixture(self, event_xml, premis_schema):
         assert isinstance(exml, etree._Element)
         assert isinstance(premis_schema, etree.XMLSchema)
         # validate event fixture doc against premis v2.3 XSD
-        premis_schema.assert_(exml)
+        premis_schema.assertValid(exml)
 
     def test_returns_event(self, event_xml):
         tree = etree.fromstring(event_xml.obj_xml)
@@ -232,7 +232,7 @@ def test_validate_agent_fixture(self, agent_xml, premis_schema):
         assert isinstance(axml, etree._Element)
         assert isinstance(premis_schema, etree.XMLSchema)
         # validate agent fixture doc against premis v2.3 XSD
-        premis_schema.assert_(axml)
+        premis_schema.assertValid(axml)
 
     def test_returns_agent(self, agent_xml):
         agent = presentation.premisAgentXMLToObject(agent_xml.obj_xml)
@@ -279,7 +279,7 @@ def test_raises_exception_when_agent_identifier_is_missing(self, agent_xml):
             presentation.premisAgentXMLToObject(etree.tostring(xml_obj))
 
         expected_message = "Unable to set 'agent_identifier'"
-        assert expected_message in str(e), 'The exception message matches'
+        assert expected_message in str(e.value), 'The exception message matches'
 
     def test_sets_agent_type(self, agent_xml):
         agent = presentation.premisAgentXMLToObject(agent_xml.obj_xml)
@@ -294,7 +294,7 @@ def test_raises_exception_when_agent_type_is_missing(self, agent_xml):
             presentation.premisAgentXMLToObject(etree.tostring(xml_obj))
 
         expected_message = "Unable to set 'agent_type'"
-        assert expected_message in str(e), 'The exception message matches'
+        assert expected_message in str(e.value), 'The exception message matches'
 
     def test_sets_agent_name(self, agent_xml):
         agent = presentation.premisAgentXMLToObject(agent_xml.obj_xml)
@@ -309,7 +309,7 @@ def test_raises_exception_when_agent_name_is_missing(self, agent_xml):
             presentation.premisAgentXMLToObject(etree.tostring(xml_obj))
 
         expected_message = "Unable to set 'agent_name'"
-        assert expected_message in str(e), 'The exception message matches'
+        assert expected_message in str(e.value), 'The exception message matches'
 
     def test_sets_agent_note(self, agent_xml):
         agent = presentation.premisAgentXMLToObject(agent_xml.obj_xml)
@@ -332,7 +332,7 @@ def test_validate_event_fixture(self, event_xml, premis_schema):
         assert isinstance(exml, etree._Element)
         assert isinstance(premis_schema, etree.XMLSchema)
         # validate event fixture doc against premis v2.3 XSD
-        premis_schema.assert_(exml)
+        premis_schema.assertValid(exml)
 
     def test_returns_correct_event_object(self, event_xml):
         tree = etree.fromstring(event_xml.entry_xml)
@@ -528,7 +528,7 @@ def test_link_object_role(self):
     def test_validate_eventxml(self, premis_schema):
         event = factories.EventFactory()
         event_xml = presentation.objectToPremisEventXML(event)
-        premis_schema.assert_(event_xml)
+        premis_schema.assertValid(event_xml)
 
 
 @pytest.mark.django_db
@@ -583,7 +583,7 @@ def test_agent_type(self):
     def test_validate_agentxml(self, premis_schema):
         agent = factories.AgentFactory()
         agent_xml = presentation.objectToAgentXML(agent)
-        premis_schema.assert_(agent_xml)
+        premis_schema.assertValid(agent_xml)
 
 
 @pytest.mark.django_db
diff --git a/tests/test_views.py b/tests/test_views.py
index a16cdcd..b9ea5f7 100644
--- a/tests/test_views.py
+++ b/tests/test_views.py
@@ -129,7 +129,7 @@ def test_json_agent_payload(rf):
     agent = factories.AgentFactory.create()
     request = rf.get('/')
     response = views.json_agent(request, agent.agent_identifier)
-    payload = json.loads(response.content)
+    payload = json.loads(response.content.decode('utf-8'))
 
     assert agent.get_absolute_url() in payload['id']
     assert payload['type'] == agent.agent_type
@@ -182,7 +182,8 @@ def test_eventXML(rf):
     request = rf.get('/')
     response = views.eventXML(request)
     assert response.status_code == 200
-    assert "So you would like XML for the event with identifier" in response.content
+    assert b"So you would like XML for the event with identifier" in \
+           response.content
 
 
 def test_findEvent_returns_ok(rf):
@@ -231,8 +232,8 @@ def test_findEvent_finds_multiple_events(rf):
     new_event, old_event = sorted([event1, event2], key=lambda e: e.event_date_time)
 
     # Check that only the oldest event is present in the xml content.
-    assert old_event.event_identifier in response.content
-    assert new_event.event_identifier not in response.content
+    assert old_event.event_identifier in response.content.decode('utf-8')
+    assert new_event.event_identifier not in response.content.decode('utf-8')
 
 
 class TestAppAgent:
@@ -269,7 +270,7 @@ def test_post_response_content(self, rf, agent_xml):
         response = views.app_agent(request)
 
         identifier = agent_xml.identifier
-        assert identifier in response.content
+        assert identifier in response.content.decode('utf-8')
 
     @pytest.mark.xfail(reason='POST request without body raises uncaught exception.')
     def test_post_without_body_is_handled(self, rf):
@@ -341,8 +342,8 @@ def test_put_response_content(self, agent_xml, rf):
 
         updated_agent = models.Agent.objects.get(agent_identifier=identifier)
 
-        assert updated_agent.agent_name in response.content
-        assert updated_agent.agent_type in response.content
+        assert updated_agent.agent_name in response.content.decode('utf-8')
+        assert updated_agent.agent_type in response.content.decode('utf-8')
 
     def test_get_with_identifier_returns_ok(self, rf):
         agent = factories.AgentFactory.create()
@@ -360,12 +361,12 @@ def test_get_with_identifier_response_content(self, rf):
         agent = factories.AgentFactory.create()
         request = rf.get('/')
         response = views.app_agent(request, agent.agent_identifier)
-        assert agent.agent_identifier in response.content
+        assert agent.agent_identifier in response.content.decode('utf-8')
 
     def test_head_without_identifier(self, rf):
         request = rf.head('/')
         response = views.app_agent(request)
-        assert response.content == '', 'The message body must be empty'
+        assert response.content == b'', b'The message body must be empty'
         assert response.status_code == 200
 
     def test_head_and_get_headers_match_without_identifier(self, rf):
@@ -383,7 +384,7 @@ def test_head_with_identifier(self, rf):
         agent = factories.AgentFactory.create()
         request = rf.head('/')
         response = views.app_agent(request, agent.agent_identifier)
-        assert response.content == '', 'The message body must be empty'
+        assert response.content == b'', b'The message body must be empty'
         assert response.status_code == 200
 
     def test_head_and_get_headers_match_with_identifier(self, rf):
@@ -409,12 +410,12 @@ def response_has_event(self, response, event):
         xml = objectify.fromstring(response.content)
         if len(xml.entry) != 1:
             return False
-        if event.event_identifier not in response.content:
+        if event.event_identifier not in response.content.decode('utf-8'):
             return False
         return True
 
     def response_includes_event(self, response, event):
-        return event.event_identifier in response.content
+        return event.event_identifier in response.content.decode('utf-8')
 
     def test_post_returns_created(self, event_xml, rf):
         request = rf.post(
@@ -445,7 +446,7 @@ def test_post_response_content(self, event_xml, rf):
 
         response = views.app_event(request)
         identifier = event_xml.identifier
-        assert identifier in response.content
+        assert identifier in response.content.decode('utf-8')
 
     def test_post_creates_event(self, event_xml, rf):
         assert models.Event.objects.count() == 0
@@ -458,6 +459,20 @@ def test_post_creates_event(self, event_xml, rf):
         views.app_event(request)
         assert models.Event.objects.count() == 1
 
+    def test_post_DuplicateEventError(self, event_xml, rf):
+        request = rf.post(
+            '/',
+            event_xml.entry_xml,
+            content_type='application/xml',
+            HTTP_HOST='example.com')
+
+        # Try to POST the same event twice.
+        views.app_event(request)
+        response = views.app_event(request)
+        assert response.status_code == 409
+        expected_response = "An event with id='{}' exists.".format(event_xml.identifier)
+        assert expected_response in response.content.decode('utf-8')
+
     def test_put_returns_ok(self, event_xml, rf):
         identifier = event_xml.identifier
         factories.EventFactory.create(event_identifier=identifier)
@@ -496,8 +511,7 @@ def test_list_number_of_events(self, rf):
         factories.EventFactory.create_batch(self.RESULTS_PER_PAGE * 2)
         request = rf.get('/')
         response = views.app_event(request)
-        xml = objectify.fromstring(response.content)
-
+        xml = objectify.fromstring(response.content.decode('utf-8'))
         assert len(xml.entry) == self.RESULTS_PER_PAGE
 
     @pytest.mark.xfail(reason='Global name DATE_FORMAT is not defined.')
@@ -528,7 +542,6 @@ def test_list_filtering_by_linking_object_id(self, rf):
         url = '/?link_object_id={0}'.format(linking_object.object_identifier)
         request = rf.get(url)
         response = views.app_event(request)
-
         assert self.response_has_event(response, event)
 
     def test_list_filtering_by_event_outcome(self, rf):
@@ -575,8 +588,7 @@ def test_list_ordering_descending(self, rf):
         # Pure Python vs the Django ORM sort items with matching keys differently.
         request = rf.get('?orderby=event_identifier&orderdir=descending')
         response = views.app_event(request)
-
-        list_events = objectify.fromstring(response.content).entry
+        list_events = objectify.fromstring(response.content.decode('utf-8')).entry
         ordered_event_ids = [f.title for f in list_events]
         event_ids = [f.event_identifier for f in events]
 
@@ -610,7 +622,7 @@ def test_get_with_identifier_content(self, rf):
         event = factories.EventFactory.create()
         request = rf.get('/', HTTP_HOST='example.com')
         response = views.app_event(request, event.event_identifier)
-        assert event.event_identifier in response.content
+        assert event.event_identifier in response.content.decode('utf-8')
 
     def test_delete_returns_ok(self, rf):
         event = factories.EventFactory.create()
@@ -633,7 +645,7 @@ def test_delete_response_content(self, rf):
         event = factories.EventFactory.create()
         request = rf.delete('/', HTTP_HOST='example.com')
         response = views.app_event(request, event.event_identifier)
-        assert event.event_identifier in response.content
+        assert event.event_identifier in response.content.decode('utf-8')
 
     def test_delete_removes_event(self, rf):
         event = factories.EventFactory.create()
@@ -644,7 +656,7 @@ def test_delete_removes_event(self, rf):
     def test_head_without_identifier(self, rf):
         request = rf.head('/')
         response = views.app_event(request)
-        assert response.content == '', 'The message body must be empty'
+        assert response.content == b'', b'The message body must be empty'
         assert response.status_code == 200
 
     def test_head_and_get_headers_match_without_identifier(self, rf):
@@ -662,7 +674,7 @@ def test_head_with_identifier(self, rf):
         event = factories.EventFactory.create()
         request = rf.head('/')
         response = views.app_event(request, event.event_identifier)
-        assert response.content == '', 'The message body must be empty'
+        assert response.content == b'', b'The message body must be empty'
         assert response.status_code == 200
 
     def test_head_and_get_headers_match_with_identifier(self, rf):
@@ -744,7 +756,7 @@ class TestJsonEventSearch:
 
     def response_has_entry(self, response, event):
         """True if the event is the only Event in the response content."""
-        data = json.loads(response.content)
+        data = json.loads(response.content.decode('utf-8'))
         entries = data['feed']['entry']
         filtered_entry = entries[0]
 
@@ -755,7 +767,7 @@ def response_has_entry(self, response, event):
         return True
 
     def response_includes_event(self, response, event):
-        events = json.loads(response.content)['feed']['entry']
+        events = json.loads(response.content.decode('utf-8'))['feed']['entry']
         event_ids = [e['identifier'] for e in events]
         return event.event_identifier in event_ids
 
@@ -775,7 +787,7 @@ def test_no_results(self, rf):
         """
         request = rf.get('/')
         response = views.json_event_search(request)
-        data = json.loads(response.content)
+        data = json.loads(response.content.decode('utf-8'))
         assert data.get('feed') is not None
         assert data.get('feed', {}).get('entry') is not None
         assert not len(data.get('feed', {}).get('entry'))
@@ -786,14 +798,14 @@ def test_results_per_page(self, rf):
         factories.EventFactory.create_batch(per_page*4)
         request = rf.get('/')
         response = views.json_event_search(request)
-        data = json.loads(response.content)
+        data = json.loads(response.content.decode('utf-8'))
         assert len(data['feed']['entry']) == per_page
 
     def test_opensearch_query(self, rf):
         factories.EventFactory.create_batch(10)
         request = rf.get('/fakefield=true')
         response = views.json_event_search(request)
-        data = json.loads(response.content)
+        data = json.loads(response.content.decode('utf-8'))
 
         assert data['feed']['opensearch:Query'] == request.GET
 
@@ -801,7 +813,7 @@ def test_opensearch_itemsPerPage(self, rf):
         factories.EventFactory.create_batch(10)
         request = rf.get('/')
         response = views.json_event_search(request)
-        data = json.loads(response.content)
+        data = json.loads(response.content.decode('utf-8'))
 
         assert data['feed']['opensearch:itemsPerPage'] == self.RESULTS_PER_PAGE
 
@@ -809,7 +821,7 @@ def test_opensearch_startIndex(self, rf):
         factories.EventFactory.create_batch(10)
         request = rf.get('/')
         response = views.json_event_search(request)
-        data = json.loads(response.content)
+        data = json.loads(response.content.decode('utf-8'))
 
         assert data['feed']['opensearch:startIndex'] == '1'
 
@@ -818,7 +830,7 @@ def test_opensearch_totalResults(self, rf):
         factories.EventFactory.create_batch(num_events)
         request = rf.get('/')
         response = views.json_event_search(request)
-        data = json.loads(response.content)
+        data = json.loads(response.content.decode('utf-8'))
 
         assert data['feed']['opensearch:totalResults'] == num_events
 
@@ -827,7 +839,7 @@ def test_pagination_links(self, rf):
         factories.EventFactory.create_batch(num_events)
         request = rf.get('/?page=2')
         response = views.json_event_search(request)
-        data = json.loads(response.content)
+        data = json.loads(response.content.decode('utf-8'))
 
         assert len(data['feed']['link']) == 5
 
diff --git a/tests/urls.py b/tests/urls.py
index 2252770..9ac5370 100644
--- a/tests/urls.py
+++ b/tests/urls.py
@@ -1,7 +1,7 @@
 import os
 
 from django.conf.urls import include, url
-import settings
+from . import settings
 
 from django.contrib import admin
 admin.autodiscover()
diff --git a/tox.ini b/tox.ini
old mode 100644
new mode 100755
index 83650cb..fdae8fe
--- a/tox.ini
+++ b/tox.ini
@@ -8,8 +8,8 @@ exclude = *migrations/*
 
 [tox]
 envlist=
-    py27-django111
-    flake8
+    py3{6,7}-django111
+    py37-flake8
 
 [testenv]
 passenv =
@@ -18,12 +18,13 @@ passenv =
     # In docker, tests run under mysql, because that PES_BACKEND is explicitly
     # set in docker-compose.
     PES_BACKEND
-basepython = python2.7
+basepython = python3
 whitelist_externals =
     python
     pip
 deps =
     pipenv
+skip_install = true
 commands =
     pipenv install --dev --ignore-pipfile
 
@@ -36,11 +37,12 @@ commands =
     # Reset to original dependencies.
     pipenv install --dev --ignore-pipfile
 
-[testenv:flake8]
-basepython = python2.7
+[testenv:py37-flake8]
+basepython = python3.7
 deps =
     pipenv
     flake8
+skip_install = true
 commands =
     pipenv install --dev --ignore-pipfile
     pipenv run flake8 setup.py premis_event_service tests