Dripline seems to throw an error when ports are assigned to RabbitMQ

If you assign host-ports to the Rabbit-Mq container with:
```
ports:
      - "8080:8080"
```
in the docker-compose.yaml file you get the following error with every container based on the dripline-python image:

`/library/core.cc(369): AMQP Library Exception caught while creating channel: (-5) hostname lookup failed`