Issues/16 print out gem versions on a --verbose

This prints out a list of versions for all gem based plugins.

It's a WIP because I wanted to verify the rubygems support for legacy ruby. This uses features introduced in the 1.8.0 / 2011-04-34 rubygems release.

![Screenshot](http://dl.dropboxusercontent.com/s/t7m25ihovb9q6uo/2014-05-30%20at%2012.18%20PM.png)