Buildpack for Heroku

[pjaspers]

It would be nice if you could just use a buildpack to set the sha.

Todo:

• Find out if buildpacks are "stackable"
• Find out if sha is available in buildpack (I believe it is)

[pjaspers]

Stackable buildpacks? Yes => https://devcenter.heroku.com/articles/using-multiple-buildpacks-for-an-app

[pjaspers]

Sha is available SOURCE_VERSION => https://devcenter.heroku.com/articles/buildpack-api