foreman reads from .env. manage.py
doesn't. Let's fix that.
pip install django-dotenv
Pop open manage.py. Add:
import dotenv
dotenv.read_dotenv()
You have to pass in __file__ so that we know where to find the .env file.
You can also pass an explicit path to the .env file, or to the directory
where it lives. It's smart, it'll figure it out.
That's it. Now go 12 factor the crap out of something.