validator don't detect wrong scheduling / parents settings

[msiebeneicher]

The current validator for chronos jobs don't detect issues like this:

{
  "schedule":"R/2017-03-17T08:52:00Z/P1D",
  "scheduleTimeZone":"Europe/Berlin",
  "epsilon":"PT15M",
  "name":"job-name-a",
  "command":"echo jobA",
  "description":"",
  "owner":"",
  "ownerName":"",
  "parents": [
      "job-name-b"
  ],
  "async":false,
  "executor":"",
  "disabled":false,
  "softError":false,
  "cpus":"0.1",
  "mem":"32",
  "disk":"24",
  "highPriority":false,
  "retries": 0
}