It's up to you how you install Garufa dependencies for development and testing, just be sure you have installed dependencies listed in the .gemspec. If you want to let bundler handle this, you can generate a Gemfile from the .gemspec and then run bundle install.
$ bundle init --gemspec=garufa.gemspec
$ bundle install
Once you have dependencies installed, run rake test (or just rake).
$ rake
Pull requests are welcome!