Bump to 0.3.2
Aruba should be the runtime dependency, not just development dependen…
…cy, and also bump to 0.3.1
Bump version to 0.3.0 after introducing `gemspec` support.
Update Appraisal itself to use `gemspec`, and update Gemfile.
Bump version to 0.2.0
Initial commit: basic rake tasks for running with different gemfiles