Merge branch 'leipert-upgrade-karma' into 'master'

Update karma: 2.0.4 -> ^3.0.0

See merge request gitlab-org/gitlab-ce!21593

package.json

@@ -133,7 +133,7 @@
     "jasmine-core": "^2.9.0",
     "jasmine-diff": "^0.1.3",
     "jasmine-jquery": "^2.1.1",
-    "karma": "^2.0.4",
+    "karma": "^3.0.0",
     "karma-chrome-launcher": "^2.2.0",
     "karma-coverage-istanbul-reporter": "^1.4.2",
     "karma-jasmine": "^1.1.2",