Bump mocha from 6.0.1 to 6.2.2

Bumps [mocha](https://github.com/mochajs/mocha) from 6.0.1 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@v6.0.1...v6.2.2)

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

Author: dependabot-preview[bot]