Remove docker_init.sh.unused script, and comment out calling docker_init.sh in docker-compose.yml

[afred]

Because

calling docker_init.sh in docker-compose.yml fails because the script got renamed, because we don't use it in development anymore.

NOTE: there is a similar script in mlavalon-docker that we use for our Kubernetes environment called rails_init.sh which runs migrations and a few other things.

Done when

• docker_init.sh.unused is removed
• directive to run command docker_init.sh is removed from docker-compose.yml
• can build avalon and test containers locally with docker-compose