Unified expected output to always eprintln so outputs can be piped to
other processes. Added debug_eprintln and switched all occurances of
debug_println.
Implemented custom command builder with nicer api suited for my needs.
Also returned error if there are no containers in
`scripts::postgres::get_containers`.
We just called `manage` inside docker instead of
`exec appserver python manage.py`. Now we make assumption that django
app is running in docker-compose in service named `appserver`.
While fixing this bug we also refactored for `shell`, `makemigrations`
and `migrate` to all call `manage` under the hood to avoid repeating code.
Made initial command scopes
d -> docker related commands
dc -> docker compose related commands
dj -> django related commands
pg -> postgres related commands
Matej Janezic