Bump minitest from 5.11.2 to 5.11.3
Bump minitest from 5.11.2 to 5.11.3

Bumps [minitest](https://github.com/seattlerb/minitest) from 5.11.2 to 5.11.3.
- [Changelog](https://github.com/seattlerb/minitest/blob/master/History.rdoc)
- [Commits](https://github.com/seattlerb/minitest/commits)
levups/http-tester