Remove Minitest.

Library/Homebrew/cask/Gemfile

Library/Homebrew/cask/Gemfile.lock

Library/Homebrew/dev-cmd/tests.rb

Library/Homebrew/test/Gemfile

Library/Homebrew/test/Gemfile.lock

Library/Homebrew/test/support/helper/fs_leak_logger.rb

...brew/test/support/helper/integration_command_test_case.rb

Library/Homebrew/test/support/helper/lifecycle_enforcer.rb

...st/support/helper/spec/shared_context/integration_test.rb

Library/Homebrew/test/support/helper/test_case.rb

Library/Homebrew/test/testing_env.rb

docs/brew.1.html

manpages/brew.1