Bump mocha from 5.2.0 to 6.2.2

Bumps [mocha](https://github.com/mochajs/mocha) from 5.2.0 to 6.2.2.
- [Release notes](https://github.com/mochajs/mocha/releases)
- [Changelog](https://github.com/mochajs/mocha/blob/master/CHANGELOG.md)
- [Commits](mochajs/mocha@v5.2.0...v6.2.2)

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

package.json

@@ -66,7 +66,7 @@
     "karma-mocha-reporter": "^2.2.5",
     "karma-sourcemap-loader": "^0.3.7",
     "karma-webpack": "^4.0.2",
-    "mocha": "^5.2.0",
+    "mocha": "^6.2.2",
     "nodemon": "^2.0.2",
     "nyc": "^13.3.0",
     "ts-loader": "^6.2.1",