Added Celery worker docker container

This docker container uses the Blender Cloud image, but a different entry
point. It is not intended to be network-reachable from the outside world.
All it needs are connections to the databases (mongo, redis, rabbit).

docker/4_run/run.docker

@@ -42,8 +42,7 @@ RUN a2enmod rewrite && a2enmod wsgi-py36
 
 ADD apache2.conf /etc/apache2/apache2.conf
 ADD 000-default.conf /etc/apache2/sites-available/000-default.conf
-ADD docker-entrypoint.sh /docker-entrypoint.sh
-ADD manage.sh /manage.sh
+ADD *.sh /
 
 # Remove some empty top-level directories we won't use anyway.
 RUN rmdir /media /home 2>/dev/null || true