Copy from bundler/spec/support/helpers.rb(sevral methods)
Copy and paste from bundler/spec/spec_helper.rb
Add rspec to development dependency
Add my_command, mami methods
Add cli exit
Copy from bundler

carlhuda/bundler/blob/master/spec/support/path.rb
ariejan/battlestation/blob/master/spec/spec_helper.rb
Use Spec::Path
Add lib method
Copy from bundler :-)
Use error message, instead of exit status

I do not understand controlling exit status yet