Get the boilerplate started

[jensneuhaus]

Please have the basic infrastructure ready:

• [x] Python (3.7) & Django setup (2.2)
• [x] settings.py working in a way, that we can easy change or extend it
• [x] Django-environ & .env.example
• [x] CircleCI working
• [x] Pipenv used
• [x] py.test & Coverage
• [x] Sentry
• [x] RQ
• [x] Docker for Postgres / Redis
• [x] Heroku deployment possible (app.json, Procfile, Whitenoise)
• [x] https://devcenter.heroku.com/articles/heroku-local#run-your-app-locally-using-foreman
• [x] Werkzeug, iPython, django-extensions, django-debug-toolbar and ipdb installed for local debugging
• [x] black installed