Domain in Nginx config file, waitress as www-data

Read BIOSTAR_HOSTNAME from production.env and use it to configure Nginx biostar site file.
If BIOSTAR_HOSTNAME starts with 'www.' then redirect the non-www wesbite, otherwise the opposite.
Run waitress as www-data user.
Run cronjob update index as www-data user.
Create DB only if it does not already exist.

Still TODO:
- use unix sockets to connect waitress and nginx.
- make docker_webapp completely could-agnostic.
- add logrotate.