save stacks using alias
you have a Gemfile. why not check in Gemfile.lock?
if .ruby-gemset and .ruby-version aren't included in the repo, .gitignore them.

many contributors will be using rbenv/rvm and will use these files.
merge upstream
show_ip option
Merge pull request #6 from adamjacobbecker/master

Add 'show_ip' option to lease command