Add ubuntu-15.04 to supported OS
Add ubuntu-15.04 to supported OS

ppp0/puppet-packages,njam/puppet-packages,vrenetic/puppet-packages,cargomedia/puppet-packages,ppp0/puppet-packages,njam/puppet-packages,njam/puppet-packages,cargomedia/puppet-packages,vrenetic/puppet-packages,vrenetic/puppet-packages,njam/puppet-packages,vrenetic/puppet-packages,cargomedia/puppet-packages,njam/puppet-packages,ppp0/puppet-packages,vrenetic/puppet-packages,cargomedia/puppet-packages,vrenetic/puppet-packages,cargomedia/puppet-packages,ppp0/puppet-packages,ppp0/puppet-packages