This is useful for development, when there is no
nginx server to serve assets.

As suggested by @elelay on
#32 (comment)

This keeps crashing with
` ModuleNotFoundError: No module named 'django_nose'`
even though the package is installed. Let's ignore for now.

The now-reverted changed made the use of the scripts less generic for other
uses.

`manage.py runserver` is not intended for serving production traffic

https://docs.djangoproject.com/en/1.8/ref/django-admin/#runserver-port-or-address-port

used in containers depending on postresql readiness.
No need for full psql command: the simple psql.py script is enough.

 - enhanced wait-for-postgres.py:
    1. waits for DB
    2. if not running migrate, exit with error message
       if tables are missing
 - move base to a different file otherwise it's also started
   and two web services are running.

wait for postgres + check db initialized

Python 3.7 is not yet supported

There is no sudo available in the Docker environment.

Let's just move the `apt-get` call command to a variable,
and override it in Makefile call in the Dockerfile.

There was a breaking change recently in Postgres Docker image:
```
Error: Database is uninitialized and superuser password is not specified.
       You must specify POSTGRES_PASSWORD for the superuser. Use
       "-e POSTGRES_PASSWORD=password" to set it in "docker run".

       You may also use POSTGRES_HOST_AUTH_METHOD=trust to allow all connections
       without a password. This is *not* recommended. See PostgreSQL
       documentation about "trust":
       https://www.postgresql.org/docs/current/auth-trust.html
```

This may not be the best setting, but let's go for this.

See docker-library/postgres#681

Without it, the step `compilemessages` fails.

This is one of the few requirements for whitenoise to just work.

See http://whitenoise.evans.io/en/stable/django.html

(This had been done in cdcb34f, but probably lost in a master merge)

Some fixes for the Docker setup