Health check fails on scheduler under DCOS 1.12

[gisjedi]

The current Marathon health check on the Scale scheduler app fails under DCOS 1.12. I've found a replacement health check that works, but it needs to be tested across all supported DCOS versions.

[gisjedi]

The proper health check for the scheduler is:

    {
      "gracePeriodSeconds": 300,
      "intervalSeconds": 30,
      "maxConsecutiveFailures": 3,
      "timeoutSeconds": 20,
      "delaySeconds": 15,
      "protocol": "COMMAND",
      "command": {
        "value": "ps -ef | grep 'manage.py scale_scheduler' | grep -v grep > /dev/null"
      }
    }