Updated package dependencies.

.travis.yml

@@ -10,9 +10,11 @@ matrix:
       env: TOXENV=py37
     - python: 3.8
       env: TOXENV=py38
+    - python: 3.9
+      env: TOXENV=py39
     - python: pypy3
       env: TOXENV=pypy3
-    - python: 3.8
+    - python: 3.9
       env: TOXENV=lint,docs
       install:
         - pip install tox

requirements/dev-py2.txt

@@ -5,16 +5,16 @@
 #    pip-compile --output-file=requirements/dev-py2.txt requirements/dev.in
 #
 atomicwrites==1.4.0       # via pytest
-attrs==20.2.0             # via pytest
+attrs==20.3.0             # via pytest
 backports.functools-lru-cache==1.6.1  # via wcwidth
 click==7.1.2              # via pip-tools
-colorama==0.4.3           # via pytest
+colorama==0.4.4           # via pytest
 configparser==4.0.2       # via importlib-metadata
 contextlib2==0.6.0.post1  # via importlib-metadata
 coverage==5.3             # via pytest-cov
 funcsigs==1.0.2           # via mock, pytest
 importlib-metadata==2.0.0  # via pluggy, pytest
-lxml==4.5.2               # via -r requirements/dev.in
+lxml==4.6.1               # via -r requirements/dev.in
 mock==3.0.5               # via -r requirements/dev.in
 more-itertools==5.0.0     # via pytest
 packaging==20.4           # via pytest
@@ -28,8 +28,8 @@ pytest==4.6.11            # via -r requirements/dev.in, pytest-cov
 scandir==1.10.0           # via pathlib2
 six==1.15.0               # via mock, more-itertools, packaging, pathlib2, pip-tools, pytest
 wcwidth==0.2.5            # via pytest
-wheezy.caching==0.1.133   # via -r requirements/dev.in
-wheezy.core==0.1.156      # via -r requirements/dev.in
+wheezy.caching==2.0.0     # via -r requirements/dev.in
+wheezy.core==2.0.0        # via -r requirements/dev.in
 zipp==1.2.0               # via importlib-metadata
 
 # The following packages are considered to be unsafe in a requirements file:

requirements/dev-py3.txt

@@ -5,24 +5,24 @@
 #    pip-compile --output-file=requirements/dev-py3.txt requirements/dev.in
 #
 atomicwrites==1.4.0       # via pytest
-attrs==20.2.0             # via pytest
+attrs==20.3.0             # via pytest
 click==7.1.2              # via pip-tools
-colorama==0.4.3           # via pytest
+colorama==0.4.4           # via pytest
 coverage==5.3             # via pytest-cov
-iniconfig==1.0.1          # via pytest
-lxml==4.5.2; platform_system != 'Windows'               # via -r requirements/dev.in
+iniconfig==1.1.1          # via pytest
+lxml==4.6.1; implementation_name != 'pypy'               # via -r requirements/dev.in
 mock==4.0.2               # via -r requirements/dev.in
 packaging==20.4           # via pytest
 pip-tools==5.3.1          # via -r requirements/dev.in
 pluggy==0.13.1            # via pytest
 py==1.9.0                 # via pytest
 pyparsing==2.4.7          # via packaging
 pytest-cov==2.10.1        # via -r requirements/dev.in
-pytest==6.1.1             # via -r requirements/dev.in, pytest-cov
+pytest==6.1.2             # via -r requirements/dev.in, pytest-cov
 six==1.15.0               # via packaging, pip-tools
-toml==0.10.1              # via pytest
-wheezy.caching==0.1.133   # via -r requirements/dev.in
-wheezy.core==0.1.156      # via -r requirements/dev.in
+toml==0.10.2              # via pytest
+wheezy.caching==2.0.0     # via -r requirements/dev.in
+wheezy.core==2.0.0        # via -r requirements/dev.in
 
 # The following packages are considered to be unsafe in a requirements file:
 # pip

requirements/docs.txt

@@ -8,29 +8,29 @@ alabaster==0.7.12         # via sphinx
 babel==2.8.0              # via sphinx
 certifi==2020.6.20        # via requests
 chardet==3.0.4            # via requests
-colorama==0.4.3           # via sphinx
+colorama==0.4.4           # via sphinx
 docutils==0.16            # via sphinx
 idna==2.10                # via requests
 imagesize==1.2.0          # via sphinx
 jinja2==2.11.2            # via sphinx
 markupsafe==1.1.1         # via jinja2
 packaging==20.4           # via sphinx
-pygments==2.7.1           # via sphinx
+pygments==2.7.2           # via sphinx
 pyparsing==2.4.7          # via packaging
-pytz==2020.1              # via babel
+pytz==2020.4              # via babel
 requests==2.24.0          # via sphinx
 six==1.15.0               # via packaging
 snowballstemmer==2.0.0    # via sphinx
 sphinx-rtd-theme==0.5.0   # via -r requirements/docs.in
-sphinx==3.2.1             # via sphinx-rtd-theme
+sphinx==3.3.0             # via sphinx-rtd-theme
 sphinxcontrib-applehelp==1.0.2  # via sphinx
 sphinxcontrib-devhelp==1.0.2  # via sphinx
 sphinxcontrib-htmlhelp==1.0.3  # via sphinx
 sphinxcontrib-jsmath==1.0.1  # via sphinx
 sphinxcontrib-qthelp==1.0.3  # via sphinx
 sphinxcontrib-serializinghtml==1.1.4  # via sphinx
-urllib3==1.25.10          # via requests
-wheezy.core==0.1.156      # via -r requirements/docs.in
+urllib3==1.25.11          # via requests
+wheezy.core==2.0.0        # via -r requirements/docs.in
 
 # The following packages are considered to be unsafe in a requirements file:
 # setuptools

setup.py

@@ -59,6 +59,7 @@
         "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
+        "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: Implementation :: CPython",
         "Programming Language :: Python :: Implementation :: PyPy",
         "Topic :: Internet :: WWW/HTTP",

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py27,py37,py38,pypy3,lint,docs
+envlist = py27,py37,py38,py39,pypy3,lint,docs
 skipsdist = True
 
 [testenv]
@@ -8,6 +8,7 @@ deps =
   py27: -r requirements/dev-py2.txt
   py37: -r requirements/dev-py3.txt
   py38: -r requirements/dev-py3.txt
+  py39: -r requirements/dev-py3.txt
   pypy3: -r requirements/dev-py3.txt
 commands =
   pytest -q -x --disable-pytest-warnings --doctest-modules \