Add foreman_one plugin

rubygem-opennebula (green):
http://koji.katello.org/koji/taskinfo?taskID=139459 (f19)
http://koji.katello.org/koji/taskinfo?taskID=139460 (el6)
http://koji.katello.org/koji/taskinfo?taskID=139461 (el7)

rubygem-foreman_one (green):
http://koji.katello.org/koji/taskinfo?taskID=139465 (f19)
http://koji.katello.org/koji/taskinfo?taskID=139466 (el6)
http://koji.katello.org/koji/taskinfo?taskID=139467 (el7)

![screenshot from 2014-08-12 14 12 02](https://cloud.githubusercontent.com/assets/482089/3890721/6489bf5a-2222-11e4-8908-75e0317eec27.png)
![screenshot from 2014-08-12 14 12 19](https://cloud.githubusercontent.com/assets/482089/3890722/679fb802-2222-11e4-8559-91b650361e99.png)

You plan to tag post merge, right?