Merge pull request #37 from pine/greenkeeper/karma-4.0.1

Update karma to the latest version 🚀

Author: pine

package.json

@@ -21,7 +21,7 @@
   },
   "devDependencies": {
     "chai": "^4.1.2",
-    "karma": "^3.1.4",
+    "karma": "^4.0.1",
     "karma-mocha": "^1.1.1",
     "karma-mocha-reporter": "^2.0.4",
     "karma-phantomjs-launcher": "^1.0.0",