chore(deps): bump commander from 6.2.0 to 6.2.1

Bumps [commander](https://github.com/tj/commander.js) from 6.2.0 to 6.2.1.
- [Release notes](https://github.com/tj/commander.js/releases)
- [Changelog](https://github.com/tj/commander.js/blob/master/CHANGELOG.md)
- [Commits](tj/commander.js@v6.2.0...v6.2.1)

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