Let PostgreSQL handles logs

[pilou-]

Fix this issue:

$ http POST localhost:80/api/auth/login email=admin@example.com password=mysecretpassword
{"error": true, "login": false, "message": "Database doesn't seem reachable."}

Since the builds with Ubuntu Focal are enabled (e25f5eb), supervisord fails to start PostgreSQL because it wasn't allowed to write to the PostgreSQL log file.

And disable extraneous log files.

Fixes #16.

[frankrousseau]

Great, thank you @pilou- !