In .gitignore don't ignore bin. This overrides setting in .gitignore_global.
Add lib/bs_ruby_sort/version.rb
Add bs_ruby_sort.gemspec
Change Gemfile to use bs_ruby_sort.gemspec
In array_sort_test.rb change from test/unit to minitest. Run bundle install --path vendor/bundle to install minitest. Let bundler update Gemfile.lock.

All unit tests pass.
Move array_sort.rb from lib to lib/bs_ruby_sort. All unit tests pass.
In README.md change headings.