removed heroku plugin from compile script
removed heroku plugin from compile script

Sage-Bionetworks/heroku-buildpack-scala,heroku/heroku-buildpack-scala,Scalingo/scala-buildpack,phdezann/heroku-buildpack-scala,shunjikonishi/heroku-buildpack-scala-compiled,phdezann/heroku-buildpack-scala,KimStebel/heroku-buildpack-scala,KimStebel/heroku-buildpack-scala,Scalingo/scala-buildpack,heroku/heroku-buildpack-scala,Javilete/buildpack,yannickdeturck/heroku-buildpack-scala,yannickdeturck/heroku-buildpack-scala,shunjikonishi/heroku-buildpack-scala-compiled,hpcloud/heroku-buildpack-scala,Luze26/heroku-buildpack-scala,Javilete/buildpack,agideon/heroku-buildpack-scala,agideon/heroku-buildpack-scala,hpcloud/heroku-buildpack-scala,Sage-Bionetworks/heroku-buildpack-scala,Luze26/heroku-buildpack-scala