Bump mocha from 2.5.3 to 6.2.1
Bump mocha from 2.5.3 to 6.2.1

Bumps [mocha](https://github.com/mochajs/mocha) from 2.5.3 to 6.2.1.
- [Release notes](https://github.com/mochajs/mocha/releases)
- [Changelog](https://github.com/mochajs/mocha/blob/v6.2.1/CHANGELOG.md)
- [Commits](https://github.com/mochajs/mocha/compare/v2.5.3...v6.2.1)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
andreafalzetti/passwordless-nodecache