Bump mocha from 3.5.3 to 6.2.2

Bumps [mocha](https://github.com/mochajs/mocha) from 3.5.3 to 6.2.2.
- [Release notes](https://github.com/mochajs/mocha/releases)
- [Changelog](https://github.com/mochajs/mocha/blob/master/CHANGELOG.md)
- [Commits](https://github.com/mochajs/mocha/compare/v3.5.3...v6.2.2)

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

package.json

@@ -112,7 +112,7 @@
     "karma-sourcemap-loader": "^0.3.7",
     "karma-spec-reporter": "^0.0.31",
     "karma-webpack": "^3.0.5",
-    "mocha": "^3.0.2",
+    "mocha": "^6.2.2",
     "multispinner": "^0.2.1",
     "node-loader": "^0.6.0",
     "require-dir": "^0.3.0",