Get all pipeline-based webhooks

Example response

{
  "results": [
    {
      "event": "STAGE_CREATE",
      "targetUrl": "{targetUrl}",
      "pipelineKey": "agptYWlsCA9AkM",
      "userKey": "agptgID0Cgw",
      "key": "agptYIDA",
      "creationDate": 1458603027590,
      "lastSavedTimestamp": 1458603027599
    }
  ]
}