Add rbenv-ruby 2.2.3 and 2.1.7 to all CI machines
Add rbenv-ruby 2.2.3 and 2.1.7 to all CI machines

Includes fix for http://blog.rubygems.org/2015/05/14/CVE-2015-3900.html

boffbowsh/ci-puppet,boffbowsh/ci-puppet,boffbowsh/ci-puppet,boffbowsh/ci-puppet,alphagov/ci-puppet,alphagov/ci-puppet,alphagov/ci-puppet,alphagov/ci-puppet