["bug"] Heroku staging

[jlubken]

Description:

Heroku staging fails here: https://github.com/CodeForPhilly/chime/runs/629740327

It should be using a docker deployment to match the linode deployment. The correct fix is to modify https://github.com/CodeForPhilly/chime/blob/develop/.github/workflows/heroku.yml to use docker like #572 so that there is a single deployment process.

As a potential quick fix, downgrade the syntax in setup.py to allow for old versions of setuptools like heroku's default setuptools. However, I believe something is still missing in the Pipfile, Pipfile.lock. I expect the penn_chime module to be missing.

Expected behavior:

I expect the staging deployment to match the production deployment and use the docker image.

What I got instead:

Heroku is attempting to use Pipenv.