Bump karma from 2.0.5 to 6.4.1

Bumps [karma](https://github.com/karma-runner/karma) from 2.0.5 to 6.4.1.
- [Release notes](https://github.com/karma-runner/karma/releases)
- [Changelog](https://github.com/karma-runner/karma/blob/master/CHANGELOG.md)
- [Commits](karma-runner/karma@v2.0.5...v6.4.1)

---
updated-dependencies:
- dependency-name: karma
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

package.json

@@ -126,7 +126,7 @@
     "jasmine-core": "^2.4.1",
     "jasmine-reporters": "^2.3.2",
     "json-loader": "^0.5.4",
-    "karma": "^2.0.2",
+    "karma": "^6.4.1",
     "karma-chrome-launcher": "^3.1.0",
     "karma-firefox-launcher": "^1.0.0",
     "karma-ie-launcher": "^1.0.0",