diff --git a/package.json b/package.json
index 08aceee..ac905e3 100644
--- a/package.json
+++ b/package.json
@@ -21,7 +21,7 @@
     "heimdalljs-logger": "^0.1.7"
   },
   "devDependencies": {
-    "chai": "3.5.0",
-    "mocha": "3.2.0"
+    "chai": "4.1.2",
+    "mocha": "5.1.1"
   }
 }
diff --git a/yarn.lock b/yarn.lock
index 6ceafca..0fb2f23 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -6,44 +6,49 @@ assertion-error@^1.0.1:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/assertion-error/-/assertion-error-1.0.2.tgz#13ca515d86206da0bac66e834dd397d87581094c"
 
-balanced-match@^0.4.1:
-  version "0.4.2"
-  resolved "https://registry.yarnpkg.com/balanced-match/-/balanced-match-0.4.2.tgz#cb3f3e3c732dc0f01ee70b403f302e61d7709838"
+balanced-match@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/balanced-match/-/balanced-match-1.0.0.tgz#89b4d199ab2bee49de164ea02b89ce462d71b767"
 
-brace-expansion@^1.0.0:
-  version "1.1.6"
-  resolved "https://registry.yarnpkg.com/brace-expansion/-/brace-expansion-1.1.6.tgz#7197d7eaa9b87e648390ea61fc66c84427420df9"
+brace-expansion@^1.1.7:
+  version "1.1.11"
+  resolved "https://registry.yarnpkg.com/brace-expansion/-/brace-expansion-1.1.11.tgz#3c7fcbf529d87226f3d2f52b966ff5271eb441dd"
   dependencies:
-    balanced-match "^0.4.1"
+    balanced-match "^1.0.0"
     concat-map "0.0.1"
 
-browser-stdout@1.3.0:
-  version "1.3.0"
-  resolved "https://registry.yarnpkg.com/browser-stdout/-/browser-stdout-1.3.0.tgz#f351d32969d32fa5d7a5567154263d928ae3bd1f"
+browser-stdout@1.3.1:
+  version "1.3.1"
+  resolved "https://registry.yarnpkg.com/browser-stdout/-/browser-stdout-1.3.1.tgz#baa559ee14ced73452229bad7326467c61fabd60"
 
-chai@3.5.0:
-  version "3.5.0"
-  resolved "https://registry.yarnpkg.com/chai/-/chai-3.5.0.tgz#4d02637b067fe958bdbfdd3a40ec56fef7373247"
+chai@4.1.2:
+  version "4.1.2"
+  resolved "https://registry.yarnpkg.com/chai/-/chai-4.1.2.tgz#0f64584ba642f0f2ace2806279f4f06ca23ad73c"
   dependencies:
     assertion-error "^1.0.1"
-    deep-eql "^0.1.3"
-    type-detect "^1.0.0"
+    check-error "^1.0.1"
+    deep-eql "^3.0.0"
+    get-func-name "^2.0.0"
+    pathval "^1.0.0"
+    type-detect "^4.0.0"
 
-commander@2.9.0:
-  version "2.9.0"
-  resolved "https://registry.yarnpkg.com/commander/-/commander-2.9.0.tgz#9c99094176e12240cb22d6c5146098400fe0f7d4"
-  dependencies:
-    graceful-readlink ">= 1.0.0"
+check-error@^1.0.1:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/check-error/-/check-error-1.0.2.tgz#574d312edd88bb5dd8912e9286dd6c0aed4aac82"
+
+commander@2.11.0:
+  version "2.11.0"
+  resolved "https://registry.yarnpkg.com/commander/-/commander-2.11.0.tgz#157152fd1e7a6c8d98a5b715cf376df928004563"
 
 concat-map@0.0.1:
   version "0.0.1"
   resolved "https://registry.yarnpkg.com/concat-map/-/concat-map-0.0.1.tgz#d8a96bd77fd68df7793a73036a3ba0d5405d477b"
 
-debug@2.2.0:
-  version "2.2.0"
-  resolved "https://registry.yarnpkg.com/debug/-/debug-2.2.0.tgz#f87057e995b1a1f6ae6a4960664137bc56f039da"
+debug@3.1.0:
+  version "3.1.0"
+  resolved "https://registry.yarnpkg.com/debug/-/debug-3.1.0.tgz#5bb5a0672628b64149566ba16819e61518c67261"
   dependencies:
-    ms "0.7.1"
+    ms "2.0.0"
 
 debug@^2.2.0:
   version "2.3.3"
@@ -51,15 +56,15 @@ debug@^2.2.0:
   dependencies:
     ms "0.7.2"
 
-deep-eql@^0.1.3:
-  version "0.1.3"
-  resolved "https://registry.yarnpkg.com/deep-eql/-/deep-eql-0.1.3.tgz#ef558acab8de25206cd713906d74e56930eb69f2"
+deep-eql@^3.0.0:
+  version "3.0.1"
+  resolved "https://registry.yarnpkg.com/deep-eql/-/deep-eql-3.0.1.tgz#dfc9404400ad1c8fe023e7da1df1c147c4b444df"
   dependencies:
-    type-detect "0.1.1"
+    type-detect "^4.0.0"
 
-diff@1.4.0:
-  version "1.4.0"
-  resolved "https://registry.yarnpkg.com/diff/-/diff-1.4.0.tgz#7f28d2eb9ee7b15a97efd89ce63dcfdaa3ccbabf"
+diff@3.5.0:
+  version "3.5.0"
+  resolved "https://registry.yarnpkg.com/diff/-/diff-3.5.0.tgz#800c0dd1e0a8bfbc95835c202ad220fe317e5a12"
 
 escape-string-regexp@1.0.5:
   version "1.0.5"
@@ -69,28 +74,32 @@ fs.realpath@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/fs.realpath/-/fs.realpath-1.0.0.tgz#1504ad2523158caa40db4a2787cb01411994ea4f"
 
-glob@7.0.5:
-  version "7.0.5"
-  resolved "https://registry.yarnpkg.com/glob/-/glob-7.0.5.tgz#b4202a69099bbb4d292a7c1b95b6682b67ebdc95"
+get-func-name@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/get-func-name/-/get-func-name-2.0.0.tgz#ead774abee72e20409433a066366023dd6887a41"
+
+glob@7.1.2:
+  version "7.1.2"
+  resolved "https://registry.yarnpkg.com/glob/-/glob-7.1.2.tgz#c19c9df9a028702d678612384a6552404c636d15"
   dependencies:
     fs.realpath "^1.0.0"
     inflight "^1.0.4"
     inherits "2"
-    minimatch "^3.0.2"
+    minimatch "^3.0.4"
     once "^1.3.0"
     path-is-absolute "^1.0.0"
 
-"graceful-readlink@>= 1.0.0":
-  version "1.0.1"
-  resolved "https://registry.yarnpkg.com/graceful-readlink/-/graceful-readlink-1.0.1.tgz#4cafad76bc62f02fa039b2f94e9a3dd3a391a725"
+growl@1.10.3:
+  version "1.10.3"
+  resolved "https://registry.yarnpkg.com/growl/-/growl-1.10.3.tgz#1926ba90cf3edfe2adb4927f5880bc22c66c790f"
 
-growl@1.9.2:
-  version "1.9.2"
-  resolved "https://registry.yarnpkg.com/growl/-/growl-1.9.2.tgz#0ea7743715db8d8de2c5ede1775e1b45ac85c02f"
+has-flag@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/has-flag/-/has-flag-2.0.0.tgz#e8207af1cc7b30d446cc70b734b5e8be18f88d51"
 
-has-flag@^1.0.0:
-  version "1.0.0"
-  resolved "http://registry.npmjs.org/has-flag/-/has-flag-1.0.0.tgz#9d9e793165ce017a00f00418c43f942a7b1d11fa"
+he@1.1.1:
+  version "1.1.1"
+  resolved "https://registry.yarnpkg.com/he/-/he-1.1.1.tgz#93410fd21b009735151f8868c2f271f3427e23fd"
 
 heimdalljs-logger@^0.1.7:
   version "0.1.7"
@@ -116,62 +125,11 @@ inherits@2:
   version "2.0.3"
   resolved "https://registry.yarnpkg.com/inherits/-/inherits-2.0.3.tgz#633c2c83e3da42a502f52466022480f4208261de"
 
-json3@3.3.2:
-  version "3.3.2"
-  resolved "https://registry.yarnpkg.com/json3/-/json3-3.3.2.tgz#3c0434743df93e2f5c42aee7b19bcb483575f4e1"
-
-lodash._baseassign@^3.0.0:
-  version "3.2.0"
-  resolved "https://registry.yarnpkg.com/lodash._baseassign/-/lodash._baseassign-3.2.0.tgz#8c38a099500f215ad09e59f1722fd0c52bfe0a4e"
-  dependencies:
-    lodash._basecopy "^3.0.0"
-    lodash.keys "^3.0.0"
-
-lodash._basecopy@^3.0.0:
-  version "3.0.1"
-  resolved "https://registry.yarnpkg.com/lodash._basecopy/-/lodash._basecopy-3.0.1.tgz#8da0e6a876cf344c0ad8a54882111dd3c5c7ca36"
-
-lodash._basecreate@^3.0.0:
-  version "3.0.3"
-  resolved "https://registry.yarnpkg.com/lodash._basecreate/-/lodash._basecreate-3.0.3.tgz#1bc661614daa7fc311b7d03bf16806a0213cf821"
-
-lodash._getnative@^3.0.0:
-  version "3.9.1"
-  resolved "https://registry.yarnpkg.com/lodash._getnative/-/lodash._getnative-3.9.1.tgz#570bc7dede46d61cdcde687d65d3eecbaa3aaff5"
-
-lodash._isiterateecall@^3.0.0:
-  version "3.0.9"
-  resolved "https://registry.yarnpkg.com/lodash._isiterateecall/-/lodash._isiterateecall-3.0.9.tgz#5203ad7ba425fae842460e696db9cf3e6aac057c"
-
-lodash.create@3.1.1:
-  version "3.1.1"
-  resolved "https://registry.yarnpkg.com/lodash.create/-/lodash.create-3.1.1.tgz#d7f2849f0dbda7e04682bb8cd72ab022461debe7"
-  dependencies:
-    lodash._baseassign "^3.0.0"
-    lodash._basecreate "^3.0.0"
-    lodash._isiterateecall "^3.0.0"
-
-lodash.isarguments@^3.0.0:
-  version "3.1.0"
-  resolved "https://registry.yarnpkg.com/lodash.isarguments/-/lodash.isarguments-3.1.0.tgz#2f573d85c6a24289ff00663b491c1d338ff3458a"
-
-lodash.isarray@^3.0.0:
+minimatch@3.0.4, minimatch@^3.0.4:
   version "3.0.4"
-  resolved "https://registry.yarnpkg.com/lodash.isarray/-/lodash.isarray-3.0.4.tgz#79e4eb88c36a8122af86f844aa9bcd851b5fbb55"
-
-lodash.keys@^3.0.0:
-  version "3.1.2"
-  resolved "https://registry.yarnpkg.com/lodash.keys/-/lodash.keys-3.1.2.tgz#4dbc0472b156be50a0b286855d1bd0b0c656098a"
-  dependencies:
-    lodash._getnative "^3.0.0"
-    lodash.isarguments "^3.0.0"
-    lodash.isarray "^3.0.0"
-
-minimatch@^3.0.2:
-  version "3.0.3"
-  resolved "https://registry.yarnpkg.com/minimatch/-/minimatch-3.0.3.tgz#2a4e4090b96b2db06a9d7df01055a62a77c9b774"
+  resolved "https://registry.yarnpkg.com/minimatch/-/minimatch-3.0.4.tgz#5166e286457f03306064be5497e8dbb0c3d32083"
   dependencies:
-    brace-expansion "^1.0.0"
+    brace-expansion "^1.1.7"
 
 minimist@0.0.8:
   version "0.0.8"
@@ -183,30 +141,30 @@ mkdirp@0.5.1:
   dependencies:
     minimist "0.0.8"
 
-mocha@3.2.0:
-  version "3.2.0"
-  resolved "https://registry.yarnpkg.com/mocha/-/mocha-3.2.0.tgz#7dc4f45e5088075171a68896814e6ae9eb7a85e3"
+mocha@5.1.1:
+  version "5.1.1"
+  resolved "https://registry.yarnpkg.com/mocha/-/mocha-5.1.1.tgz#b774c75609dac05eb48f4d9ba1d827b97fde8a7b"
   dependencies:
-    browser-stdout "1.3.0"
-    commander "2.9.0"
-    debug "2.2.0"
-    diff "1.4.0"
+    browser-stdout "1.3.1"
+    commander "2.11.0"
+    debug "3.1.0"
+    diff "3.5.0"
     escape-string-regexp "1.0.5"
-    glob "7.0.5"
-    growl "1.9.2"
-    json3 "3.3.2"
-    lodash.create "3.1.1"
+    glob "7.1.2"
+    growl "1.10.3"
+    he "1.1.1"
+    minimatch "3.0.4"
     mkdirp "0.5.1"
-    supports-color "3.1.2"
-
-ms@0.7.1:
-  version "0.7.1"
-  resolved "https://registry.yarnpkg.com/ms/-/ms-0.7.1.tgz#9cd13c03adbff25b65effde7ce864ee952017098"
+    supports-color "4.4.0"
 
 ms@0.7.2:
   version "0.7.2"
   resolved "https://registry.yarnpkg.com/ms/-/ms-0.7.2.tgz#ae25cf2512b3885a1d95d7f037868d8431124765"
 
+ms@2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/ms/-/ms-2.0.0.tgz#5608aeadfc00be6c2901df5f9861788de0d597c8"
+
 once@^1.3.0:
   version "1.4.0"
   resolved "https://registry.yarnpkg.com/once/-/once-1.4.0.tgz#583b1aa775961d4b113ac17d9c50baef9dd76bd1"
@@ -217,23 +175,23 @@ path-is-absolute@^1.0.0:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/path-is-absolute/-/path-is-absolute-1.0.1.tgz#174b9268735534ffbc7ace6bf53a5a9e1b5c5f5f"
 
+pathval@^1.0.0:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/pathval/-/pathval-1.1.0.tgz#b942e6d4bde653005ef6b71361def8727d0645e0"
+
 rsvp@~3.2.1:
   version "3.2.1"
   resolved "https://registry.yarnpkg.com/rsvp/-/rsvp-3.2.1.tgz#07cb4a5df25add9e826ebc67dcc9fd89db27d84a"
 
-supports-color@3.1.2:
-  version "3.1.2"
-  resolved "https://registry.yarnpkg.com/supports-color/-/supports-color-3.1.2.tgz#72a262894d9d408b956ca05ff37b2ed8a6e2a2d5"
+supports-color@4.4.0:
+  version "4.4.0"
+  resolved "https://registry.yarnpkg.com/supports-color/-/supports-color-4.4.0.tgz#883f7ddabc165142b2a61427f3352ded195d1a3e"
   dependencies:
-    has-flag "^1.0.0"
+    has-flag "^2.0.0"
 
-type-detect@0.1.1:
-  version "0.1.1"
-  resolved "https://registry.yarnpkg.com/type-detect/-/type-detect-0.1.1.tgz#0ba5ec2a885640e470ea4e8505971900dac58822"
-
-type-detect@^1.0.0:
-  version "1.0.0"
-  resolved "https://registry.yarnpkg.com/type-detect/-/type-detect-1.0.0.tgz#762217cc06db258ec48908a1298e8b95121e8ea2"
+type-detect@^4.0.0:
+  version "4.0.8"
+  resolved "https://registry.yarnpkg.com/type-detect/-/type-detect-4.0.8.tgz#7646fb5f18871cfbb7749e69bd39a6388eb7450c"
 
 wrappy@1:
   version "1.0.2"