Updated readme [skip ci]
Updated readme [skip ci]

yannickdeturck/heroku-buildpack-scala,agideon/heroku-buildpack-scala,yannickdeturck/heroku-buildpack-scala,agideon/heroku-buildpack-scala,heroku/heroku-buildpack-scala,Scalingo/scala-buildpack,Scalingo/scala-buildpack,heroku/heroku-buildpack-scala