add back missing heroku config file which somehow got moved in a previous commit
add back missing heroku config file which somehow got moved in a previous commit

forresty/integrity,integrity/integrity,faradayio/ci1,dkastner/prism_ci,integrity/integrity,erik-escobedo/integrity,forresty/integrity,faradayio/ci1,p/integrity,p/integrity,integrity/integrity,erik-escobedo/integrity