Fixed two heredoc bugs with sbt-extras
Fixed two heredoc bugs with sbt-extras

hpcloud/heroku-buildpack-scala,heroku/heroku-buildpack-scala,phdezann/heroku-buildpack-scala,Javilete/buildpack,KimStebel/heroku-buildpack-scala,agideon/heroku-buildpack-scala,yannickdeturck/heroku-buildpack-scala,Scalingo/scala-buildpack,KimStebel/heroku-buildpack-scala,phdezann/heroku-buildpack-scala,agideon/heroku-buildpack-scala,hpcloud/heroku-buildpack-scala,Javilete/buildpack,heroku/heroku-buildpack-scala,yannickdeturck/heroku-buildpack-scala,Scalingo/scala-buildpack