Added region and zone members to task model.

[gisjedi]

Missing region and zone members resulted in stack trace when making calls
to client.get_app under DCOS EE 1.11+. I've resolved the problem with addition of both kwargs to MarathonTask. It was unclear to me how I could adequately test this with the behave tests. The main problem I had was in identifying how to enable the Marathon region and zone values in the open-source releases. I'm happy to provide test coverage if you can provide a pointer to how I'd accomplish this. Regardless, I've tested to ensure this resolves my individual problem.

Stack trace snippet experienced when using marathon package against DCOS EE 1.11.8 cluster deployed in AWS:

  File "/usr/lib/python2.7/site-packages/marathon/client.py", line 252, in get_app
    return self._parse_response(response, MarathonApp, resource_name='app')
  File "/usr/lib/python2.7/site-packages/marathon/client.py", line 74, in _parse_response
    return clazz.from_json(target)
  File "/usr/lib/python2.7/site-packages/marathon/models/base.py", line 43, in from_json
    return cls(**{to_snake_case(k): v for k, v in attributes.items()})
  File "/usr/lib/python2.7/site-packages/marathon/models/app.py", line 169, in __init__
    for t in (tasks or [])
  File "/usr/lib/python2.7/site-packages/marathon/models/base.py", line 43, in from_json
    return cls(**{to_snake_case(k): v for k, v in attributes.items()})
TypeError: __init__() got an unexpected keyword argument 'zone'

This is the response from the /v2/apps/scale-elasticsearch/ Marathon API for reference:

{
  "app": {
    "id": "/scale-elasticsearch",
    "backoffFactor": 1.15,
    "backoffSeconds": 1,
    "container": {
      "type": "DOCKER",
      "docker": {
        "forcePullImage": false,
        "image": "elasticsearch:2-alpine",
        "parameters": [],
        "privileged": false
      },
      "volumes": [],
      "portMappings": [
        {
          "containerPort": 9200,
          "hostPort": 0,
          "labels": {
            "VIP_0": "/scale-elasticsearch:9200"
          },
          "protocol": "tcp",
          "servicePort": 10104
        }
      ]
    },
    "cpus": 1,
    "disk": 0,
    "executor": "",
    "healthChecks": [
      {
        "gracePeriodSeconds": 300,
        "intervalSeconds": 60,
        "maxConsecutiveFailures": 3,
        "portIndex": 0,
        "protocol": "MESOS_HTTP",
        "ipProtocol": "IPv4",
        "timeoutSeconds": 20,
        "delaySeconds": 15
      }
    ],
    "instances": 1,
    "labels": {},
    "maxLaunchDelaySeconds": 3600,
    "mem": 512,
    "gpus": 0,
    "networks": [
      {
        "mode": "container/bridge"
      }
    ],
    "requirePorts": false,
    "upgradeStrategy": {
      "maximumOverCapacity": 1,
      "minimumHealthCapacity": 1
    },
    "version": "2018-12-27T17:42:53.175Z",
    "versionInfo": {
      "lastScalingAt": "2018-12-27T17:42:53.175Z",
      "lastConfigChangeAt": "2018-12-27T17:42:53.175Z"
    },
    "killSelection": "YOUNGEST_FIRST",
    "unreachableStrategy": {
      "inactiveAfterSeconds": 0,
      "expungeAfterSeconds": 0
    },
    "tasksStaged": 0,
    "tasksRunning": 1,
    "tasksHealthy": 1,
    "tasksUnhealthy": 0,
    "deployments": [],
    "tasks": [
      {
        "appId": "/scale-elasticsearch",
        "healthCheckResults": [
          {
            "alive": true,
            "consecutiveFailures": 0,
            "firstSuccess": "2018-12-27T17:43:14.876Z",
            "instanceId": "instance [scale-elasticsearch.marathon-d69e9176-09fe-11e9-964b-8e27d858ac7e]",
            "lastSuccess": "2018-12-27T17:43:14.876Z"
          }
        ],
        "host": "172.12.24.142",
        "id": "scale-elasticsearch.d69e9176-09fe-11e9-964b-8e27d858ac7e",
        "ipAddresses": [
          {
            "ipAddress": "172.17.0.2",
            "protocol": "IPv4"
          }
        ],
        "ports": [
          20227
        ],
        "servicePorts": [],
        "slaveId": "21f0ff64-120b-4f94-b0fb-0f886030395a-S0",
        "state": "TASK_RUNNING",
        "stagedAt": "2018-12-27T17:42:53.934Z",
        "startedAt": "2018-12-27T17:42:59.720Z",
        "version": "2018-12-27T17:42:53.175Z",
        "localVolumes": [],
        "region": "us-east-1",
        "zone": "us-east-1b"
      }
    ]
  }
}

[gisjedi]

@solarkennedy Would it be possible to cut a 0.10.x release now that this change is merged? I'd like to reference the updates in a requirements.txt file.

[solarkennedy]

@gisjedi released.

[gisjedi]

Hugely appreciate the quick turn around!