Bump minitest from 5.15.0 to 5.16.1 (#351)

Bumps [minitest](https://github.com/seattlerb/minitest) from 5.15.0 to 5.16.1.
- [Release notes](https://github.com/seattlerb/minitest/releases)
- [Changelog](https://github.com/minitest/minitest/blob/master/History.rdoc)
- [Commits](minitest/minitest@v5.15.0...v5.16.1)

---
updated-dependencies:
- dependency-name: minitest
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>