Bump css-loader from 2.0.1 to 2.1.0

Bumps [css-loader](https://github.com/webpack-contrib/css-loader) from 2.0.1 to 2.1.0.
- [Release notes](https://github.com/webpack-contrib/css-loader/releases)
- [Changelog](https://github.com/webpack-contrib/css-loader/blob/master/CHANGELOG.md)
- [Commits](https://github.com/webpack-contrib/css-loader/compare/v2.0.1...v2.1.0

)

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