Site Mist Edges Upgrades

WS /api-ws/v1/stream

{
    "subscribe": "/sites/{site_id}/mxedges"
}

{
  "event": "data",
  "channel": "/sites/67970e46-4e12-11e6-9188-0242ac110007/mxedges",
  "data": {
    "device_id": "00000000-0000-0000-1000-5c5b3524500b",
    "event_type": "fwupdate",
    "detail": {
      "timestamp": 1485381027,
      "status": "inprogress",
      "progress": 45
    }
  }
}