Add Ruby 2.0.0 to list of supported rubies
Add Ruby 2.0.0 to .travis.yml
Add require 'rubygems/command' in order to fix tests

Tests were not passing on my machine until I made those changes.
Rubygems 2.0.3.
Merge pull request #7 from sevos/patch-1

Add Ruby 2.0.0 to list of supported rubies