Update stable.pp
Update stable.pp

Updated new download location
RallySoftware/boxen-iterm2,boxen/puppet-iterm2,boxen/puppet-iterm2,boxen/puppet-iterm2,mpherg/puppet-iterm2,RallySoftware/boxen-iterm2,mpherg/puppet-iterm2,RallySoftware/boxen-iterm2,mpherg/puppet-iterm2