docker-compose.yml

* Wasn't using static_root and media_root properly: nginx was unaware of
  the folders (unless the hardcoded name "static" or "media" was used)
* There is a difference between the project name (of your choosing,
  which will be used to name folders in the server) and the name of the
  django project (the one gunicorn will use to call you project). We now
  differentiate both.