cibuildgem 0.2.1

Gems with native extensions are the main bottleneck for a user when running `bundle install`. This gem aims to provide the Ruby community an easy to opt-in and quick way to distribute their gems with precompiled binaries. This toolchain works with a native CI based compilation approach using GitHub actions. It piggyback on top of popular tools in the Ruby ecosystem that maintainers are used to such as Rake Compiler and ruby/setup-ruby.