Creates the user and the database provided by the environment variable.
These are currently duplicated in postgres.env so we might want to find
a way to have them in only one place.
I tried my best at keeping the pg_hba.conf file secure for the server,
but I am no expert so it'd be great if someone could check it out.
Need a better way to deal with config, docker uses environment variables
mostly and the application uses .go files. Keeping the two in sync will
probably end up being annoying.
Not tested yet as the current postgres dump is incompatible with the
application. We need to fix ourselve to one schema and stick to it for
whatever database backend we support.
