Bump eslint from 6.8.0 to 7.12.1

Bumps [eslint](https://github.com/eslint/eslint) from 6.8.0 to 7.12.1.
- [Release notes](https://github.com/eslint/eslint/releases)
- [Changelog](https://github.com/eslint/eslint/blob/master/CHANGELOG.md)
- [Commits](eslint/eslint@v6.8.0...v7.12.1)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>
Signed-off-by: Christoph Wurst <christoph@winzerhof-wurst.at>

Author: dependabot-preview[bot]