Update minitest requirement from ~> 5.3, < 5.15 to ~> 5.3, < 5.16
Update minitest requirement from ~> 5.3, < 5.15 to ~> 5.3, < 5.16

Updates the requirements on [minitest](https://github.com/seattlerb/minitest) to permit the latest version.
- [Release notes](https://github.com/seattlerb/minitest/releases)
- [Changelog](https://github.com/seattlerb/minitest/blob/master/History.rdoc)
- [Commits](https://github.com/seattlerb/minitest/compare/v5.3.0...v5.15.0)

---
updated-dependencies:
- dependency-name: minitest
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
test-kitchen/kitchen-pester