chore(package): update karma to version 4.3.0

Closes #18

Author: greenkeeper[bot]

package.json

@@ -31,7 +31,7 @@
     "jasmine-core": "^3.0.0",
     "jit-grunt": "^0.10.0",
     "jshint-stylish": "^2.2.1",
-    "karma": "^2.0.0",
+    "karma": "^4.3.0",
     "karma-coverage": "^1.1.1",
     "karma-jasmine": "*",
     "karma-phantomjs-launcher": "*",