chore(package): update karma to version 5.0.9

Closes #39

Author: greenkeeper[bot]

package.json

@@ -66,7 +66,7 @@
         "imports-loader": "^0.8.0",
         "istanbul": "^0.4.5",
         "istanbul-instrumenter-loader": "^3.0.1",
-        "karma": "^4.0.1",
+        "karma": "^5.0.9",
         "karma-chai": "^0.1.0",
         "karma-chai-sinon": "^0.1.5",
         "karma-chrome-launcher": "^2.2.0",