chore(package): update karma to version 2.0.4

Closes #60

Author: greenkeeper[bot]

package.json

@@ -89,7 +89,7 @@
     "execa": "^0.7.0",
     "glob": "^7.1.1",
     "jasmine-core": "^2.5.2",
-    "karma": "^1.5.0",
+    "karma": "^2.0.4",
     "karma-chrome-launcher": "^2.1.1",
     "karma-cli": "^1.0.1",
     "karma-coverage": "^1.1.1",