Support for non-git buildpacks

[Cryptophobia]

From @szymonpk on February 20, 2017 8:48

Currently BUILDPACK_URL has to be a git repo.

There is (at least one) a buildpack which is distributed in pre-complied form (*.tgz). It's possible to pass link to the archive in heroku, buildpack in git requires some manual action (complication), so it won't work in Workflow.

Is it possible to re-implement this in Workflow?

As workaround I've unpacked provided archive and pushed it to separate git repo.

Copied from original issue: deis/slugbuilder#132

[Cryptophobia]

From @bacongobbler on February 21, 2017 19:44

Sure, if someone wants to implement .tgz and .tar.gz support for BUILDPACK_URL it can be done here. One would just need to check the file extension and do a HTTP GET if it's a tarball (.tar.gz or .tgz extension), otherwise perform the regular git clone.