chore(package): update karma to version 4.1.0

Closes #88

Author: greenkeeper[bot]

package.json

@@ -37,7 +37,7 @@
     "coveralls": "^2.11.12",
     "cz-conventional-changelog": "^2.0.0",
     "jasmine-core": "^2.6.2",
-    "karma": "^2.0.0",
+    "karma": "^4.1.0",
     "karma-chrome-launcher": "^2.2.0",
     "karma-coverage": "^1.1.1",
     "karma-firefox-launcher": "^1.0.0",