chore(package): update karma to version 5.0.1

Closes #50

Author: greenkeeper[bot]

package.json

@@ -80,7 +80,7 @@
     "doctoc": "^1.3.0",
     "in-publish": "^2.0.0",
     "jsdoc": "^3.4.3",
-    "karma": "^4.0.1",
+    "karma": "^5.0.1",
     "karma-chrome-launcher": "^2.2.0",
     "karma-detect-browsers": "^2.2.6",
     "karma-firefox-launcher": "^1.1.0",