build(deps): bump minimist and mocha

Bumps [minimist](https://github.com/minimistjs/minimist) to 1.2.8 and updates ancestor dependency [mocha](https://github.com/mochajs/mocha). These dependencies need to be updated together.


Updates `minimist` from 1.2.5 to 1.2.8
- [Release notes](https://github.com/minimistjs/minimist/releases)
- [Changelog](https://github.com/minimistjs/minimist/blob/main/CHANGELOG.md)
- [Commits](minimistjs/minimist@v1.2.5...v1.2.8)

Updates `mocha` from 6.1.4 to 6.2.3
- [Release notes](https://github.com/mochajs/mocha/releases)
- [Changelog](https://github.com/mochajs/mocha/blob/master/CHANGELOG.md)
- [Commits](mochajs/mocha@v6.1.4...v6.2.3)

---
updated-dependencies:
- dependency-name: minimist
  dependency-type: indirect
- dependency-name: mocha
  dependency-type: direct:development
...

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

Author: dependabot[bot]