add service_port argument

[danielfrg]

There was a bug when you tried to use the lib to start a docker container in marathon. The problem was that marathon is returning a json field servicePort and the code is trying to map it to service_port which didn't exists on the __init__.

The problem only affected the response parsing, the task in marathon was created fine.

Now I was able to do it like this:

from marathon import MarathonClient
from marathon.models.container import MarathonContainer, MarathonDockerContainer, MarathonContainerPortMapping

c = MarathonClient('http://localhost:8080/')
ports = MarathonContainerPortMapping(container_port=4444)
docker = MarathonDockerContainer('danielfrg/selenium', network='BRIDGE', port_mappings=[ports])
container = MarathonContainer(docker=docker)
app = MarathonApp(container=container, mem=300, cpus=0.5)
c.create_app('selenium', app)

Thanks for the lib :)

[mbabineau]

(new in 0.7.3)
👍 thanks!