Bump karma from 4.4.1 to 6.3.16

Bumps [karma](https://github.com/karma-runner/karma) from 4.4.1 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](karma-runner/karma@v4.4.1...v6.3.16)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

package.json

@@ -50,7 +50,7 @@
     "eslint-plugin-promise": "^4.2.1",
     "eslint-plugin-standard": "^4.0.1",
     "flatpickr": "^4.6.3",
-    "karma": "^4.0.1",
+    "karma": "^6.3.16",
     "karma-chai": "^0.1.0",
     "karma-chrome-launcher": "^2.2.0",
     "karma-coverage": "^2.0.1",