chore(deps-dev): bump tslint from 6.1.1 to 6.1.2

Bumps [tslint](https://github.com/palantir/tslint) from 6.1.1 to 6.1.2.
- [Release notes](https://github.com/palantir/tslint/releases)
- [Changelog](https://github.com/palantir/tslint/blob/master/CHANGELOG.md)
- [Commits](palantir/tslint@6.1.1...6.1.2)

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