GitHub testling webhook integration issue

Request Body

{
  "zen": "Encourage flow.",
  "hook": {
    "url": "https://api.github.com/repos/watson/mongoify/hooks/2812427",
    "test_url": "https://api.github.com/repos/watson/mongoify/hooks/2812427/test",
    "id": 2812427,
    "name": "web",
    "active": true,
    "events": [
      "push"
    ],
    "config": {
      "secret": "",
      "url": "http://git.testling.com",
      "content_type": "json",
      "insecure_ssl": "0"
    },
    "last_response": {
      "code": null,
      "status": "unused",
      "message": null
    },
    "updated_at": "2014-08-17T11:47:34Z",
    "created_at": "2014-08-17T11:47:34Z"
  },
  "hook_id": 2812427
}

Request headers

Request URL: http://git.testling.com
Request method: POST
content-type: application/json
Expect: 
User-Agent: GitHub-Hookshot/5c8714b
X-GitHub-Delivery: 47435efc-2604-11e4-9b46-7fbe602db071
X-GitHub-Event: ping

Response Body

Error: empty payload

Response Headers

Connection: keep-alive
Date: Sun, 17 Aug 2014 12:06:41 GMT
Transfer-Encoding: chunked