Bump karma from 5.0.9 to 6.3.16

Bumps [karma](https://github.com/karma-runner/karma) from 5.0.9 to 6.3.16.
- [Release notes](https://github.com/karma-runner/karma/releases)
- [Changelog](https://github.com/karma-runner/karma/blob/master/CHANGELOG.md)
- [Commits](https://github.com/karma-runner/karma/compare/v5.0.9...v6.3.16)

---
updated-dependencies:
- dependency-name: karma
  dependency-type: direct:development
...

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

package.json

@@ -31,7 +31,7 @@
     "chromium": "^3.0.3",
     "eslint": "^6.8.0",
     "eslint-plugin-github": "^4.0.0",
-    "karma": "^5.0.9",
+    "karma": "^6.3.16",
     "karma-chai": "^0.1.0",
     "karma-chrome-launcher": "^3.1.0",
     "karma-mocha": "^2.0.1",