update latest vars in compile
update latest vars in compile

benmurden/heroku-buildpack-python-ember,benjaminfox/heroku-buildpack-python-geoip,skilljar/heroku-buildpack-python,heroku/heroku-buildpack-python,benjaminfox/heroku-buildpack-python-geoip,ad-m/heroku-buildpack-python,benmurden/heroku-buildpack-python-ember,Scalingo/python-buildpack,ad-m/heroku-buildpack-python,Scalingo/python-buildpack,AltSchool/heroku-buildpack-python,AltSchool/heroku-buildpack-python,heroku/heroku-buildpack-python