To install gem:

Git clone bitbucket url
git clone git@github.com:mountetna/germ.git

cd into germ directory so you can see germ.gemspec

gem build germ.gemspec

gem install germ-0.1.gem

To include in a Gemfile
paste this line into Gemfile:

gem 'germ', git:'git@github.com:mountetna/germ.git'