chore(package): update karma to version 4.2.0

Closes #103

Author: greenkeeper[bot]

package.json

@@ -72,7 +72,7 @@
     "cz-conventional-changelog": "2.0.0",
     "jasmine-core": "2.6.2",
     "jasmine-spec-reporter": "4.1.0",
-    "karma": "1.7.0",
+    "karma": "4.2.0",
     "karma-chrome-launcher": "2.1.0",
     "karma-cli": "1.0.1",
     "karma-coverage-istanbul-reporter": "1.2.1",