Fix property on readme ruby::plugin example
Fix property on readme ruby::plugin example

dgoodlad/puppet-chruby,boxen/puppet-ruby,dgoodlad/puppet-chruby,grosser/puppet-ruby,salimane/puppet-ruby,halyard/puppet-ruby,dieterdemeyer/puppet-ruby,halyard/puppet-ruby,boxen/puppet-ruby,RallySoftware/boxen-ruby,RallySoftware/boxen-ruby,grosser/puppet-ruby,dieterdemeyer/puppet-ruby,salimane/puppet-ruby