Added the possibility to easily change the ports that nginx listens to.
This is useful, for instance when Apache or Nginx already runs on the
host. With this change, it is no longer necessary to edit the
docker-compose file to modify these ports.
To deploy with alternate ports, add a `.env` file with the following
contents:
```
OPENEDX_NGINX_PORT=8080
OPENEDX_NGINX_TLSPORT=8443
```
Rabbitmq was not configured to restart on failures. It does not explain
why rabbitmq crashes (with exit code 255, see issue #80), but this should be sufficient
as a quick fix.
Duplicate "environment" statement in the docker-compose.yml was causing
the first one to be forgotten. Hence, the cms celery worker was running
with LMS settings.
Close #72
Template files are now directly loaded in the configurator container, so
that it is possible to run the configurator container directly, outside
of this project.
