Merge pull request #219 from kubernetes/greenkeeper-karma-0.13.18

Update karma to version 0.13.18 🚀

package.json

@@ -54,7 +54,7 @@
     "gulp-util": "~3.0.7",
     "gulp-watch": "~4.3.5",
     "isparta": "~4.0.0",
-    "karma": "0.13.15",
+    "karma": "0.13.18",
     "karma-browserify": "~4.4.2",
     "karma-chrome-launcher": "~0.2.2",
     "karma-coverage": "~0.5.3",