Bump karma from 3.1.4 to 4.2.0

Bumps [karma](https://github.com/karma-runner/karma) from 3.1.4 to 4.2.0.
- [Release notes](https://github.com/karma-runner/karma/releases)
- [Changelog](https://github.com/karma-runner/karma/blob/master/CHANGELOG.md)
- [Commits](karma-runner/karma@v3.1.4...v4.2.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

package.json

@@ -48,7 +48,7 @@
     "coveralls": "^3.0.2",
     "cross-env": "^5.2.0",
     "istanbul": "^0.4.5",
-    "karma": "^3.0.0",
+    "karma": "^4.2.0",
     "karma-chai": "^0.1.0",
     "karma-chrome-launcher": "^2.2.0",
     "karma-cli": "^1.0.1",