diff --git a/package.json b/package.json
index 32a4d08..88c948a 100644
--- a/package.json
+++ b/package.json
@@ -21,7 +21,7 @@
     "mocha": "6.1.4",
     "mocha-lcov-reporter": "1.3.0",
     "nyc": "14.1.1",
-    "supertest": "4.0.2"
+    "supertest": "6.0.1"
   },
   "license": "MIT",
   "dependencies": {
diff --git a/yarn.lock b/yarn.lock
index f082075..2164cb9 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -288,7 +288,7 @@ color-name@1.1.3:
   resolved "https://registry.yarnpkg.com/color-name/-/color-name-1.1.3.tgz#a7d0558bd89c42f795dd42328f740831ca53bc25"
   integrity sha1-p9BVi9icQveV3UIyj3QIMcpTvCU=
 
-combined-stream@^1.0.6, combined-stream@~1.0.6:
+combined-stream@^1.0.6, combined-stream@^1.0.8, combined-stream@~1.0.6:
   version "1.0.8"
   resolved "https://registry.yarnpkg.com/combined-stream/-/combined-stream-1.0.8.tgz#c3d45a8b34fd730631a110a8a2520682b31d5a7f"
   integrity sha512-FQN4MRfuJeHf7cBbBMJFXhKSDq+2kAArBlmRBvcvFE5BB1HZKXtSFASDhdlz9zOYwxh8lDdnvmMOe/+5cdoEdg==
@@ -305,7 +305,7 @@ commondir@^1.0.1:
   resolved "https://registry.yarnpkg.com/commondir/-/commondir-1.0.1.tgz#ddd800da0c66127393cca5950ea968a3aaf1253b"
   integrity sha1-3dgA2gxmEnOTzKWVDqloo6rxJTs=
 
-component-emitter@^1.2.0:
+component-emitter@^1.3.0:
   version "1.3.0"
   resolved "https://registry.yarnpkg.com/component-emitter/-/component-emitter-1.3.0.tgz#16e4070fba8ae29b679f2215853ee181ab2eabc0"
   integrity sha512-Rd3se6QB+sO1TwqZjscQrurpEPIfO0/yYnSin6Q/rD3mOutHvUrCAhJub3r90uNb+SESBuE0QYoB90YdfatsRg==
@@ -334,7 +334,7 @@ convert-source-map@^1.6.0:
   dependencies:
     safe-buffer "~5.1.1"
 
-cookiejar@^2.1.0:
+cookiejar@^2.1.2:
   version "2.1.2"
   resolved "https://registry.yarnpkg.com/cookiejar/-/cookiejar-2.1.2.tgz#dd8a235530752f988f9a0844f3fc589e3111125c"
   integrity sha512-Mw+adcfzPxcPeI+0WlvRrr/3lGVO0bD75SxX6811cxSh1Wbxx7xZBGK1eVtDf6si8rg2lhnUjsVLMFMfbRIuwA==
@@ -347,7 +347,7 @@ cookies@~0.7.1:
     depd "~1.1.2"
     keygrip "~1.0.3"
 
-core-util-is@1.0.2, core-util-is@~1.0.0:
+core-util-is@1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/core-util-is/-/core-util-is-1.0.2.tgz#b5fd54220aa2bc5ab57aab7140c940754503c1a7"
   integrity sha1-tf1UIgqivFq1eqtxQMlAdUUDwac=
@@ -401,7 +401,7 @@ dashdash@^1.12.0:
   dependencies:
     assert-plus "^1.0.0"
 
-debug@3.2.6, debug@^3.1.0:
+debug@3.2.6:
   version "3.2.6"
   resolved "https://registry.yarnpkg.com/debug/-/debug-3.2.6.tgz#e83d17de16d8a7efb7717edbe5fb10135eee629b"
   integrity sha512-mel+jf7nrtEl5Pn1Qx46zARXKDpBbvzezse7p7LqINmdoIk8PYP5SySaxEmYv6TZ0JyEKA1hsCId6DIhgITtWQ==
@@ -567,7 +567,7 @@ execa@^1.0.0:
     signal-exit "^3.0.0"
     strip-eof "^1.0.0"
 
-extend@^3.0.0, extend@~3.0.2:
+extend@~3.0.2:
   version "3.0.2"
   resolved "https://registry.yarnpkg.com/extend/-/extend-3.0.2.tgz#f8b1136b4071fbd8eb140aff858b1019ec2915fa"
   integrity sha512-fjquC59cD7CyW6urNXK0FBufkZcoiGG80wTuPujX590cB5Ttln20E2UB4S/WARVqhXffZl2LNgS+gQdPIIim/g==
@@ -592,6 +592,11 @@ fast-json-stable-stringify@^2.0.0:
   resolved "https://registry.yarnpkg.com/fast-json-stable-stringify/-/fast-json-stable-stringify-2.0.0.tgz#d5142c0caee6b1189f87d3a76111064f86c8bbf2"
   integrity sha1-1RQsDK7msRifh9OnYREGT4bIu/I=
 
+fast-safe-stringify@^2.0.7:
+  version "2.0.7"
+  resolved "https://registry.yarnpkg.com/fast-safe-stringify/-/fast-safe-stringify-2.0.7.tgz#124aa885899261f68aedb42a7c080de9da608743"
+  integrity sha512-Utm6CdzT+6xsDk2m8S6uL8VHxNwI6Jub+e9NYTcAms28T84pTa25GJQV9j0CY0N1rM8hK4x6grpF2BQf+2qwVA==
+
 find-cache-dir@^2.1.0:
   version "2.1.0"
   resolved "https://registry.yarnpkg.com/find-cache-dir/-/find-cache-dir-2.1.0.tgz#8d0f94cd13fe43c6c7c261a0d86115ca918c05f7"
@@ -628,7 +633,16 @@ forever-agent@~0.6.1:
   resolved "https://registry.yarnpkg.com/forever-agent/-/forever-agent-0.6.1.tgz#fbc71f0c41adeb37f96c577ad1ed42d8fdacca91"
   integrity sha1-+8cfDEGt6zf5bFd60e1C2P2sypE=
 
-form-data@^2.3.1, form-data@~2.3.2:
+form-data@^3.0.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/form-data/-/form-data-3.0.0.tgz#31b7e39c85f1355b7139ee0c647cf0de7f83c682"
+  integrity sha512-CKMFDglpbMi6PyN+brwB9Q/GOw0eAnsrEZDgcsH5Krhz5Od/haKHAX0NmQfha2zPPz0JpWzA7GJHGSnvCRLWsg==
+  dependencies:
+    asynckit "^0.4.0"
+    combined-stream "^1.0.8"
+    mime-types "^2.1.12"
+
+form-data@~2.3.2:
   version "2.3.3"
   resolved "https://registry.yarnpkg.com/form-data/-/form-data-2.3.3.tgz#dcce52c05f644f298c6a7ab936bd724ceffbf3a6"
   integrity sha512-1lLKB2Mu3aGP1Q/2eCOx0fNbRMe7XdwktwOruhfqqd0rIJWwN4Dh+E3hrPSlDCXnSR7UtZ1N38rVXm+6+MEhJQ==
@@ -637,10 +651,10 @@ form-data@^2.3.1, form-data@~2.3.2:
     combined-stream "^1.0.6"
     mime-types "^2.1.12"
 
-formidable@^1.2.0:
-  version "1.2.1"
-  resolved "https://registry.yarnpkg.com/formidable/-/formidable-1.2.1.tgz#70fb7ca0290ee6ff961090415f4b3df3d2082659"
-  integrity sha512-Fs9VRguL0gqGHkXS5GQiMCr1VhZBxz0JnJs4JmMp/2jL18Fmbzvv7vOFRU+U8TBkHEE/CX1qDXzJplVULgsLeg==
+formidable@^1.2.2:
+  version "1.2.2"
+  resolved "https://registry.yarnpkg.com/formidable/-/formidable-1.2.2.tgz#bf69aea2972982675f00865342b982986f6b8dd9"
+  integrity sha512-V8gLm+41I/8kguQ4/o1D3RIHRmhYFG4pnNyonvua+40rqcEmT4+V71yaZ3B457xbbgCsCfjSPi65u/W6vK1U5Q==
 
 fresh@~0.5.2:
   version "0.5.2"
@@ -829,11 +843,16 @@ inflight@^1.0.4:
     once "^1.3.0"
     wrappy "1"
 
-inherits@2, inherits@2.0.3, inherits@~2.0.3:
+inherits@2, inherits@2.0.3:
   version "2.0.3"
   resolved "https://registry.yarnpkg.com/inherits/-/inherits-2.0.3.tgz#633c2c83e3da42a502f52466022480f4208261de"
   integrity sha1-Yzwsg+PaQqUC9SRmAiSA9CCCYd4=
 
+inherits@^2.0.3:
+  version "2.0.4"
+  resolved "https://registry.yarnpkg.com/inherits/-/inherits-2.0.4.tgz#0fa2c64f932917c3433a0ded55363aae37416b7c"
+  integrity sha512-k/vGaX4/Yla3WzyMCvTQOXYeIHvqOKtnqBduzTHpzpQZzAskKMhZ2K+EnBiSM9zGSoIFeMpXKxa4dYeZIQqewQ==
+
 invert-kv@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/invert-kv/-/invert-kv-2.0.0.tgz#7393f5afa59ec9ff5f67a27620d11c226e3eec02"
@@ -900,11 +919,6 @@ is-typedarray@~1.0.0:
   resolved "https://registry.yarnpkg.com/is-typedarray/-/is-typedarray-1.0.0.tgz#e479c80858df0c1b11ddda6940f96011fcda4a9a"
   integrity sha1-5HnICFjfDBsR3dppQPlgEfzaSpo=
 
-isarray@~1.0.0:
-  version "1.0.0"
-  resolved "https://registry.yarnpkg.com/isarray/-/isarray-1.0.0.tgz#bb935d48582cba168c06834957a54a3e07124f11"
-  integrity sha1-u5NdSFgsuhaMBoNJV6VKPgcSTxE=
-
 isexe@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/isexe/-/isexe-2.0.0.tgz#e8fbf374dc556ff8947a10dcb0572d633f2cfa10"
@@ -1184,7 +1198,7 @@ merge-source-map@^1.1.0:
   dependencies:
     source-map "^0.6.1"
 
-methods@^1.1.1, methods@^1.1.2:
+methods@1.1.2, methods@^1.1.2:
   version "1.1.2"
   resolved "https://registry.yarnpkg.com/methods/-/methods-1.1.2.tgz#5529a4d67654134edcc5266656835b0f851afcee"
   integrity sha1-VSmk1nZUE07cxSZmVoNbD4Ua/O4=
@@ -1201,10 +1215,10 @@ mime-types@^2.1.12, mime-types@^2.1.18, mime-types@~2.1.19, mime-types@~2.1.24:
   dependencies:
     mime-db "1.40.0"
 
-mime@^1.4.1:
-  version "1.6.0"
-  resolved "https://registry.yarnpkg.com/mime/-/mime-1.6.0.tgz#32cd9e5c64553bd58d19a568af452acff04981b1"
-  integrity sha512-x0Vn8spI+wuJ1O6S7gnbaQg8Pxh4NNHb7KSINmEWKiPE4RKOplvijn+NkmYmmRgP68mc70j2EbeTFRsrswaQeg==
+mime@^2.4.6:
+  version "2.4.6"
+  resolved "https://registry.yarnpkg.com/mime/-/mime-2.4.6.tgz#e5b407c90db442f2beb5b162373d07b69affa4d1"
+  integrity sha512-RZKhC3EmpBchfTGBVb8fb+RL2cWyw/32lshnsETttkBAyAUXSGHxbEJWWRXc751DrIxG1q04b8QwMbAwkRPpUA==
 
 mimic-fn@^2.0.0:
   version "2.1.0"
@@ -1540,11 +1554,6 @@ pkg-dir@^3.0.0:
   dependencies:
     find-up "^3.0.0"
 
-process-nextick-args@~2.0.0:
-  version "2.0.0"
-  resolved "https://registry.yarnpkg.com/process-nextick-args/-/process-nextick-args-2.0.0.tgz#a37d732f4271b4ab1ad070d35508e8290788ffaa"
-  integrity sha512-MtEC1TqN0EU5nephaJ4rAtThHtC86dNN9qCuEhtshvpVBkAW5ZO7BASN9REnF9eoXGcRub+pFuKEpOHE+HbEMw==
-
 pseudomap@^1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/pseudomap/-/pseudomap-1.0.2.tgz#f052a28da70e618917ef0a8ac34c1ae5a68286b3"
@@ -1573,10 +1582,10 @@ punycode@^2.1.0:
   resolved "https://registry.yarnpkg.com/punycode/-/punycode-2.1.1.tgz#b58b010ac40c22c5657616c8d2c2c02c7bf479ec"
   integrity sha512-XRsRjdf+j5ml+y/6GKHPZbrF/8p2Yga0JPtdqTIY2Xe5ohJPD9saDJJLPvp9+NSBprVvevdXZybnj2cv8OEd0A==
 
-qs@^6.5.1:
-  version "6.7.0"
-  resolved "https://registry.yarnpkg.com/qs/-/qs-6.7.0.tgz#41dc1a015e3d581f1621776be31afb2876a9b1bc"
-  integrity sha512-VCdBRNFTX1fyE7Nb6FYoURo/SPe62QCaAyzJvUjwRaIsc+NePBEniHlvxFmmX56+HZphIGtV0XeCirBtpDrTyQ==
+qs@^6.9.4:
+  version "6.9.4"
+  resolved "https://registry.yarnpkg.com/qs/-/qs-6.9.4.tgz#9090b290d1f91728d3c22e54843ca44aea5ab687"
+  integrity sha512-A1kFqHekCTM7cz0udomYUoYNWjBebHm/5wzU/XqrBRBNWectVH0QIiN+NEcZ0Dte5hvzHwbr8+XQmguPhJ6WdQ==
 
 qs@~6.5.2:
   version "6.5.2"
@@ -1600,18 +1609,14 @@ read-pkg@^3.0.0:
     normalize-package-data "^2.3.2"
     path-type "^3.0.0"
 
-readable-stream@^2.3.5:
-  version "2.3.6"
-  resolved "https://registry.yarnpkg.com/readable-stream/-/readable-stream-2.3.6.tgz#b11c27d88b8ff1fbe070643cf94b0c79ae1b0aaf"
-  integrity sha512-tQtKA9WIAhBF3+VLAseyMqZeBjW0AHJoxOtYqSUZNJxauErmLbVm2FW1y+J/YA9dUrAC39ITejlZWhVIwawkKw==
+readable-stream@^3.6.0:
+  version "3.6.0"
+  resolved "https://registry.yarnpkg.com/readable-stream/-/readable-stream-3.6.0.tgz#337bbda3adc0706bd3e024426a286d4b4b2c9198"
+  integrity sha512-BViHy7LKeTz4oNnkcLJ+lVSL6vpiFeX6/d3oSH8zCW7UxP2onchk+vTGB143xuFjHS3deTgkKoXXymXqymiIdA==
   dependencies:
-    core-util-is "~1.0.0"
-    inherits "~2.0.3"
-    isarray "~1.0.0"
-    process-nextick-args "~2.0.0"
-    safe-buffer "~5.1.1"
-    string_decoder "~1.1.1"
-    util-deprecate "~1.0.1"
+    inherits "^2.0.3"
+    string_decoder "^1.1.1"
+    util-deprecate "^1.0.1"
 
 release-zalgo@^1.0.0:
   version "1.0.0"
@@ -1688,11 +1693,16 @@ rimraf@^2.6.2, rimraf@^2.6.3:
   dependencies:
     glob "^7.1.3"
 
-safe-buffer@5.1.2, safe-buffer@^5.0.1, safe-buffer@^5.1.2, safe-buffer@~5.1.0, safe-buffer@~5.1.1:
+safe-buffer@5.1.2, safe-buffer@^5.0.1, safe-buffer@^5.1.2, safe-buffer@~5.1.1:
   version "5.1.2"
   resolved "https://registry.yarnpkg.com/safe-buffer/-/safe-buffer-5.1.2.tgz#991ec69d296e0313747d59bdfd2b745c35f8828d"
   integrity sha512-Gd2UZBJDkXlY7GbJxfsE8/nvKkUEU1G38c1siN6QP6a9PT9MmHB8GnpscSmMJSoF8LOIrt8ud/wPtojys4G6+g==
 
+safe-buffer@~5.2.0:
+  version "5.2.1"
+  resolved "https://registry.yarnpkg.com/safe-buffer/-/safe-buffer-5.2.1.tgz#1eaf9fa9bdb1fdd4ec75f58f9cdb4e6b7827eec6"
+  integrity sha512-rp3So07KcdmmKbGvgaNxQSJr7bGVSVk5S9Eq1F+ppbRo70+YeaDxkw5Dd8NPN+GD6bjnYm2VuPuCXmpuYvmCXQ==
+
 safer-buffer@^2.0.2, safer-buffer@^2.1.0, safer-buffer@~2.1.0:
   version "2.1.2"
   resolved "https://registry.yarnpkg.com/safer-buffer/-/safer-buffer-2.1.2.tgz#44fa161b0187b9549dd84bb91802f9bd8385cd6a"
@@ -1708,6 +1718,11 @@ semver@^6.0.0:
   resolved "https://registry.yarnpkg.com/semver/-/semver-6.1.1.tgz#53f53da9b30b2103cd4f15eab3a18ecbcb210c9b"
   integrity sha512-rWYq2e5iYW+fFe/oPPtYJxYgjBm8sC4rmoGdUOgBB7VnwKt6HrL793l2voH1UlsyYZpJ4g0wfjnTEO1s1NP2eQ==
 
+semver@^7.3.2:
+  version "7.3.2"
+  resolved "https://registry.yarnpkg.com/semver/-/semver-7.3.2.tgz#604962b052b81ed0786aae84389ffba70ffd3938"
+  integrity sha512-OrOb32TeeambH6UrhtShmF7CRDqhL6/5XpPNp2DuRH6+9QLw/orhp72j87v8Qa1ScDkvrrBNpZcDejAirJmfXQ==
+
 set-blocking@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/set-blocking/-/set-blocking-2.0.0.tgz#045f9782d011ae9a6803ddd382b24392b3d890f7"
@@ -1839,12 +1854,12 @@ string-width@^3.0.0, string-width@^3.1.0:
     is-fullwidth-code-point "^2.0.0"
     strip-ansi "^5.1.0"
 
-string_decoder@~1.1.1:
-  version "1.1.1"
-  resolved "https://registry.yarnpkg.com/string_decoder/-/string_decoder-1.1.1.tgz#9cf1611ba62685d7030ae9e4ba34149c3af03fc8"
-  integrity sha512-n/ShnvDi6FHbbVfviro+WojiFzv+s8MPMHBczVePfUpDJLwoLT0ht1l4YwBCbi8pJAveEEdnkHyPyTP/mzRfwg==
+string_decoder@^1.1.1:
+  version "1.3.0"
+  resolved "https://registry.yarnpkg.com/string_decoder/-/string_decoder-1.3.0.tgz#42f114594a46cf1a8e30b0a84f56c78c3edac21e"
+  integrity sha512-hkRX8U1WjJFd8LsDJ2yQ/wWWxaopEsABU1XfkM8A+j0+85JAGppt16cr1Whg6KIbb4okU6Mql6BOj+uup/wKeA==
   dependencies:
-    safe-buffer "~5.1.0"
+    safe-buffer "~5.2.0"
 
 strip-ansi@^3.0.0, strip-ansi@^3.0.1:
   version "3.0.1"
@@ -1882,29 +1897,30 @@ strip-json-comments@2.0.1:
   resolved "https://registry.yarnpkg.com/strip-json-comments/-/strip-json-comments-2.0.1.tgz#3c531942e908c2697c0ec344858c286c7ca0a60a"
   integrity sha1-PFMZQukIwml8DsNEhYwobHygpgo=
 
-superagent@^3.8.3:
-  version "3.8.3"
-  resolved "https://registry.yarnpkg.com/superagent/-/superagent-3.8.3.tgz#460ea0dbdb7d5b11bc4f78deba565f86a178e128"
-  integrity sha512-GLQtLMCoEIK4eDv6OGtkOoSMt3D+oq0y3dsxMuYuDvaNUvuT8eFBuLmfR0iYYzHC1e8hpzC6ZsxbuP6DIalMFA==
-  dependencies:
-    component-emitter "^1.2.0"
-    cookiejar "^2.1.0"
-    debug "^3.1.0"
-    extend "^3.0.0"
-    form-data "^2.3.1"
-    formidable "^1.2.0"
-    methods "^1.1.1"
-    mime "^1.4.1"
-    qs "^6.5.1"
-    readable-stream "^2.3.5"
-
-supertest@4.0.2:
-  version "4.0.2"
-  resolved "https://registry.yarnpkg.com/supertest/-/supertest-4.0.2.tgz#c2234dbdd6dc79b6f15b99c8d6577b90e4ce3f36"
-  integrity sha512-1BAbvrOZsGA3YTCWqbmh14L0YEq0EGICX/nBnfkfVJn7SrxQV1I3pMYjSzG9y/7ZU2V9dWqyqk2POwxlb09duQ==
+superagent@6.1.0:
+  version "6.1.0"
+  resolved "https://registry.yarnpkg.com/superagent/-/superagent-6.1.0.tgz#09f08807bc41108ef164cfb4be293cebd480f4a6"
+  integrity sha512-OUDHEssirmplo3F+1HWKUrUjvnQuA+nZI6i/JJBdXb5eq9IyEQwPyPpqND+SSsxf6TygpBEkUjISVRN4/VOpeg==
   dependencies:
+    component-emitter "^1.3.0"
+    cookiejar "^2.1.2"
+    debug "^4.1.1"
+    fast-safe-stringify "^2.0.7"
+    form-data "^3.0.0"
+    formidable "^1.2.2"
     methods "^1.1.2"
-    superagent "^3.8.3"
+    mime "^2.4.6"
+    qs "^6.9.4"
+    readable-stream "^3.6.0"
+    semver "^7.3.2"
+
+supertest@6.0.1:
+  version "6.0.1"
+  resolved "https://registry.yarnpkg.com/supertest/-/supertest-6.0.1.tgz#f6b54370de85c45d6557192c8d7df604ca2c9e18"
+  integrity sha512-8yDNdm+bbAN/jeDdXsRipbq9qMpVF7wRsbwLgsANHqdjPsCoecmlTuqEcLQMGpmojFBhxayZ0ckXmLXYq7e+0g==
+  dependencies:
+    methods "1.1.2"
+    superagent "6.1.0"
 
 supports-color@6.0.0:
   version "6.0.0"
@@ -1995,7 +2011,7 @@ uri-js@^4.2.2:
   dependencies:
     punycode "^2.1.0"
 
-util-deprecate@~1.0.1:
+util-deprecate@^1.0.1:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/util-deprecate/-/util-deprecate-1.0.2.tgz#450d4dc9fa70de732762fbd2d4a28981419a0ccf"
   integrity sha1-RQ1Nyfpw3nMnYvvS1KKJgUGaDM8=