Bump underscore from 1.9.0 to 1.9.1

Bumps [underscore](https://github.com/jashkenas/underscore) from 1.9.0 to 1.9.1.
- [Release notes](https://github.com/jashkenas/underscore/releases)
- [Commits](https://github.com/jashkenas/underscore/compare/1.9.0...1.9.1

)

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