diff --git a/package-lock.json b/package-lock.json
index 92c8bf2..726fe0c 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -123,14 +123,21 @@
       }
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-      "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.6.2.tgz",
-      "integrity": "sha512-FBHEW6Jf5TB9MGBgUUA9XHkTbjXYfAUjY43ACMfmdMRHniyoMHjHjzD50OK8LGDWQwp4rWEsIq5kEqq7rvIM1g==",
+      "version": "6.12.6",
+      "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.12.6.tgz",
+      "integrity": "sha512-j3fVLgvTo527anyYyJOGTYJbG+vnnQYvE0m5mmkc1TK+nxAppkCLMIL0aZ4dblVCNoGShhm+kzE4ZUykBoMg4g==",
       "requires": {
-        "fast-deep-equal": "^2.0.1",
+        "fast-deep-equal": "^3.1.1",
         "fast-json-stable-stringify": "^2.0.0",
         "json-schema-traverse": "^0.4.1",
         "uri-js": "^4.2.2"
+      },
+      "dependencies": {
+        "fast-deep-equal": {
+          "version": "3.1.3",
+          "resolved": "https://registry.npmjs.org/fast-deep-equal/-/fast-deep-equal-3.1.3.tgz",
+          "integrity": "sha512-f3qQ9oQy9j2AhBe/H9VC91wLmKBCCU/gDOnKNAYG5hswO7BLKj09Hc5HYNz9cGI++xlpDCIgDaitVs03ATR84Q=="
+        }
       }
     },
     "ajv-keywords": {
@@ -221,7 +228,7 @@
         },
         "util": {
           "version": "0.10.3",
-          "resolved": "http://registry.npmjs.org/util/-/util-0.10.3.tgz",
+          "resolved": "https://registry.npmjs.org/util/-/util-0.10.3.tgz",
           "integrity": "sha1-evsa/lCAUkZInj23/g7TeTNqwPk=",
           "requires": {
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@@ -1394,7 +1401,7 @@
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           "version": "2.0.0",
-          "resolved": "http://registry.npmjs.org/supports-color/-/supports-color-2.0.0.tgz",
+          "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-2.0.0.tgz",
           "integrity": "sha1-U10EXOa2Nj+kARcIRimZXp3zJMc=",
           "dev": true
         }
@@ -2070,11 +2077,6 @@
       "resolved": "https://registry.npmjs.org/extsprintf/-/extsprintf-1.3.0.tgz",
       "integrity": "sha1-lpGEQOMEGnpBT4xS48V06zw+HgU="
     },
-    "fast-deep-equal": {
-      "version": "2.0.1",
-      "resolved": "https://registry.npmjs.org/fast-deep-equal/-/fast-deep-equal-2.0.1.tgz",
-      "integrity": "sha1-ewUhjd+WZ79/Nwv3/bLLFf3Qqkk="
-    },
     "fast-json-stable-stringify": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/fast-json-stable-stringify/-/fast-json-stable-stringify-2.0.0.tgz",
@@ -2171,7 +2173,8 @@
         },
         "ansi-regex": {
           "version": "2.1.1",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "aproba": {
           "version": "1.2.0",
@@ -2189,11 +2192,13 @@
         },
         "balanced-match": {
           "version": "1.0.0",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "brace-expansion": {
           "version": "1.1.11",
           "bundled": true,
+          "optional": true,
           "requires": {
             "balanced-match": "^1.0.0",
             "concat-map": "0.0.1"
@@ -2206,15 +2211,18 @@
         },
         "code-point-at": {
           "version": "1.1.0",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "concat-map": {
           "version": "0.0.1",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "console-control-strings": {
           "version": "1.1.0",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "core-util-is": {
           "version": "1.0.2",
@@ -2317,7 +2325,8 @@
         },
         "inherits": {
           "version": "2.0.3",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
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           "version": "1.3.5",
@@ -2327,6 +2336,7 @@
         "is-fullwidth-code-point": {
           "version": "1.0.0",
           "bundled": true,
+          "optional": true,
           "requires": {
             "number-is-nan": "^1.0.0"
           }
@@ -2339,17 +2349,20 @@
         "minimatch": {
           "version": "3.0.4",
           "bundled": true,
+          "optional": true,
           "requires": {
             "brace-expansion": "^1.1.7"
           }
         },
         "minimist": {
           "version": "0.0.8",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "minipass": {
           "version": "2.3.5",
           "bundled": true,
+          "optional": true,
           "requires": {
             "safe-buffer": "^5.1.2",
             "yallist": "^3.0.0"
@@ -2366,6 +2379,7 @@
         "mkdirp": {
           "version": "0.5.1",
           "bundled": true,
+          "optional": true,
           "requires": {
             "minimist": "0.0.8"
           }
@@ -2438,7 +2452,8 @@
         },
         "number-is-nan": {
           "version": "1.0.1",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "object-assign": {
           "version": "4.1.1",
@@ -2448,6 +2463,7 @@
         "once": {
           "version": "1.4.0",
           "bundled": true,
+          "optional": true,
           "requires": {
             "wrappy": "1"
           }
@@ -2523,7 +2539,8 @@
         },
         "safe-buffer": {
           "version": "5.1.2",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
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           "version": "2.1.2",
@@ -2553,6 +2570,7 @@
         "string-width": {
           "version": "1.0.2",
           "bundled": true,
+          "optional": true,
           "requires": {
             "code-point-at": "^1.0.0",
             "is-fullwidth-code-point": "^1.0.0",
@@ -2570,6 +2588,7 @@
         "strip-ansi": {
           "version": "3.0.1",
           "bundled": true,
+          "optional": true,
           "requires": {
             "ansi-regex": "^2.0.0"
           }
@@ -2608,11 +2627,13 @@
         },
         "wrappy": {
           "version": "1.0.2",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "yallist": {
           "version": "3.0.3",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         }
       }
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@@ -3236,7 +3257,7 @@
     },
     "is-accessor-descriptor": {
       "version": "0.1.6",
-      "resolved": "http://registry.npmjs.org/is-accessor-descriptor/-/is-accessor-descriptor-0.1.6.tgz",
+      "resolved": "https://registry.npmjs.org/is-accessor-descriptor/-/is-accessor-descriptor-0.1.6.tgz",
       "integrity": "sha1-qeEss66Nh2cn7u84Q/igiXtcmNY=",
       "requires": {
         "kind-of": "^3.0.2"
@@ -3270,7 +3291,7 @@
     },
     "is-data-descriptor": {
       "version": "0.1.4",
-      "resolved": "http://registry.npmjs.org/is-data-descriptor/-/is-data-descriptor-0.1.4.tgz",
+      "resolved": "https://registry.npmjs.org/is-data-descriptor/-/is-data-descriptor-0.1.4.tgz",
       "integrity": "sha1-C17mSDiOLIYCgueT8YVv7D8wG1Y=",
       "requires": {
         "kind-of": "^3.0.2"
@@ -3758,7 +3779,7 @@
         "chai-bignumber": "2.0.1",
         "datejs": "^1.0.0-rc3",
         "ethereumjs-testrpc": "6.0.3",
-        "monetha-utility-contracts": "git+https://github.com/monetha/utility-contracts.git#575bec683bea2ff522604a7cfa83a303db7be32e",
+        "monetha-utility-contracts": "git+https://github.com/monetha/utility-contracts.git",
         "openzeppelin-solidity": "^1.12.0",
         "truffle": "^4.1.14",
         "truffle-flattener": "^1.2.8"
@@ -4648,7 +4669,7 @@
         },
         "os-locale": {
           "version": "1.4.0",
-          "resolved": "http://registry.npmjs.org/os-locale/-/os-locale-1.4.0.tgz",
+          "resolved": "https://registry.npmjs.org/os-locale/-/os-locale-1.4.0.tgz",
           "integrity": "sha1-IPnxeuKe00XoveWDsT0gCYA8FNk=",
           "requires": {
             "lcid": "^1.0.0"
@@ -4693,7 +4714,7 @@
         },
         "string-width": {
           "version": "1.0.2",
-          "resolved": "http://registry.npmjs.org/string-width/-/string-width-1.0.2.tgz",
+          "resolved": "https://registry.npmjs.org/string-width/-/string-width-1.0.2.tgz",
           "integrity": "sha1-EYvfW4zcUaKn5w0hHgfisLmxB9M=",
           "requires": {
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@@ -4721,7 +4742,7 @@
         },
         "yargs": {
           "version": "4.8.1",
-          "resolved": "http://registry.npmjs.org/yargs/-/yargs-4.8.1.tgz",
+          "resolved": "https://registry.npmjs.org/yargs/-/yargs-4.8.1.tgz",
           "integrity": "sha1-wMQpJMpKqmsObaFznfshZDn53cA=",
           "requires": {
             "cliui": "^3.2.0",
@@ -4742,7 +4763,7 @@
         },
         "yargs-parser": {
           "version": "2.4.1",
-          "resolved": "http://registry.npmjs.org/yargs-parser/-/yargs-parser-2.4.1.tgz",
+          "resolved": "https://registry.npmjs.org/yargs-parser/-/yargs-parser-2.4.1.tgz",
           "integrity": "sha1-hVaN488VD/SfpRgl8DqMiA3cxcQ=",
           "requires": {
             "camelcase": "^3.0.0",
@@ -4923,7 +4944,7 @@
     },
     "strip-ansi": {
       "version": "3.0.1",
-      "resolved": "http://registry.npmjs.org/strip-ansi/-/strip-ansi-3.0.1.tgz",
+      "resolved": "https://registry.npmjs.org/strip-ansi/-/strip-ansi-3.0.1.tgz",
       "integrity": "sha1-ajhfuIU9lS1f8F0Oiq+UJ43GPc8=",
       "requires": {
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@@ -5083,7 +5104,7 @@
       "dependencies": {
         "yargs": {
           "version": "3.10.0",
-          "resolved": "http://registry.npmjs.org/yargs/-/yargs-3.10.0.tgz",
+          "resolved": "https://registry.npmjs.org/yargs/-/yargs-3.10.0.tgz",
           "integrity": "sha1-9+572FfdfB0tOMDnTvvWgdFDH9E=",
           "requires": {
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@@ -5330,7 +5351,7 @@
       "dependencies": {
         "string-width": {
           "version": "1.0.2",
-          "resolved": "http://registry.npmjs.org/string-width/-/string-width-1.0.2.tgz",
+          "resolved": "https://registry.npmjs.org/string-width/-/string-width-1.0.2.tgz",
           "integrity": "sha1-EYvfW4zcUaKn5w0hHgfisLmxB9M=",
           "requires": {
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@@ -5397,7 +5418,7 @@
           "dependencies": {
             "string-width": {
               "version": "1.0.2",
-              "resolved": "http://registry.npmjs.org/string-width/-/string-width-1.0.2.tgz",
+              "resolved": "https://registry.npmjs.org/string-width/-/string-width-1.0.2.tgz",
               "integrity": "sha1-EYvfW4zcUaKn5w0hHgfisLmxB9M=",
               "requires": {
                 "code-point-at": "^1.0.0",