pass the new envfile argument to compile
show users to use tags; encouraging use of version pinning
Merge pull request #22 from kennethreitz/patch-1

show users to use tags; encouraging use of version pinning
Merge pull request #21 from zeke/master

pass the new envfile argument to compile
Merge branch 'master' of github.com:ddollar/heroku-buildpack-multi into build-env