[Security] Bump rack from 2.0.3 to 2.0.7
[Security] Bump rack from 2.0.3 to 2.0.7

Bumps [rack](https://github.com/rack/rack) from 2.0.3 to 2.0.7. **This update includes security fixes.**
- [Release notes](https://github.com/rack/rack/releases)
- [Changelog](https://github.com/rack/rack/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rack/rack/compare/2.0.3...2.0.7)
uzyexe/chef-dev