minitest provides a complete suite of testing facilities supporting
 TDD, BDD, mocking, and benchmarking.
 .
 minitest/unit is a small and incredibly fast unit testing framework.
 It provides a rich set of assertions to make your tests clean and
 readable.
 .
 minitest/spec is a functionally complete spec engine. It hooks onto
 minitest/unit and seamlessly bridges test assertions over to spec
 expectations.
 .
 minitest/benchmark is an awesome way to assert the performance of your
 algorithms in a repeatable manner. Now you can assert that your newb
 co-worker doesn't replace your linear algorithm with an exponential
 one!
 .
 minitest/mock by Steven Baker, is a beautifully tiny mock object
 framework.
 .
 minitest/pride shows pride in testing and adds coloring to your test
 output.
 .
 minitest/unit is meant to have a clean implementation for language
 implementors that need a minimal set of methods to bootstrap a working
 test suite. For example, there is no magic involved for test-case
 discovery.