Make `:rake` task use `heroku run` instead of `heroku rake`, for compatibility with cedar stack.
Make `:rake` task use `heroku run` instead of `heroku rake`, for compatibility with cedar stack.

jqr/heroku_san,jqr/heroku_san,fastestforward/heroku_san,gfdgfd/hksan,fastestforward/heroku_san,gfdgfd/hksan