Bump underscore from 1.8.3 to 1.9.1

Bumps [underscore](https://github.com/jashkenas/underscore) from 1.8.3 to 1.9.1.
- [Release notes](https://github.com/jashkenas/underscore/releases)
- [Commits](https://github.com/jashkenas/underscore/compare/1.8.3...1.9.1

)

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