title: NSJSONSerialization return nil with a valid json
body: <p>I try to parse a response which return a valid JSON with NSJSonSerialization. But it returns nil with no error. It works with another JSON response.</p>
  
  <p>I did some search, and this could be a problem with the encoding of the JSON. I don't know how to solve it. Any idea ? </p>
  
  <pre><code>let url: NSURL = NSURL(string: urlPath)!
          self.searchRequest = NSMutableURLRequest(URL: url)
          if let searchRequest = self.searchRequest {
              searchRequest.HTTPMethod = "GET"
              let authString : String = SNCF.APIKey + ":" + ""
              let authData : NSData = authString.dataUsingEncoding(NSASCIIStringEncoding)!
              let authValue : String = "Basic " + authData.base64EncodedStringWithOptions(.EncodingEndLineWithCarriageReturn)
              searchRequest.setValue(authValue, forHTTPHeaderField: "Authorization")
  
              let queue:NSOperationQueue = NSOperationQueue()
              NSURLConnection.sendAsynchronousRequest(searchRequest, queue: queue, completionHandler:{ (response: NSURLResponse?, data: NSData?, error: NSError?) -&gt; Void in
  
              do {
  //HERE JSONRESULT WILL BE NIL
                  if let jsonResult = try NSJSONSerialization.JSONObjectWithData(data!, options: []) as? [String: [AnyObject]] {
                      print("ASynchronous\(jsonResult)")
                      if let places = jsonResult["stop_areas"] as? [[String:AnyObject]]{
                          for placeDictionary in places {
                              if let labelText = placeDictionary["label"] as? String {
                                  self.resultDatasource.append(labelText)
                              }
                          }
                          self.resultTableView.reloadData()
                      }
                  }
  //HERE NO ERROR IS CATCHED
              } catch let error as NSError {
                  print(error.localizedDescription)
              }
          })
  </code></pre>
  
  <p>Piece of my json response :</p>
  
  <pre><code>{
    "disruptions": [],
    "pagination": {
      "start_page": 0,
      "items_on_page": 100,
      "items_per_page": 100,
      "total_result": 3053
    },
    "stop_areas": [
      {
        "codes": [
          {
            "type": "CR-CI-CH",
            "value": "0080-251967-BV"
          }
        ],
        "name": "gare de Perl",
        "links": [],
        "coord": {
          "lat": "0",
          "lon": "0"
        },
        "label": "gare de Perl",
        "timezone": "Europe/Paris",
        "id": "stop_area:OCE:SA:80251967"
      },
      {
      ...
      },
      //stop_areas dictionaries object...
  ], //end stop_areas array of dictionaries
  "links": [
      {
        "href": "https://api.sncf.com/v1/coverage/sncf/stop_areas/{stop_areas.id}",
        "type": "stop_areas",
        "rel": "stop_areas",
        "templated": true
      },
      {
        "href": "https://api.sncf.com/v1/coverage/sncf/stop_areas?start_page=1",
        "type": "next",
        "templated": false
      },
      {
        "href": "https://api.sncf.com/v1/coverage/sncf/stop_areas?start_page=30.52",
        "type": "last",
        "templated": false
      },
      {
        "href": "https://api.sncf.com/v1/coverage/sncf/stop_areas",
        "type": "first",
        "templated": false
      }
    ],
    "feed_publishers": [
      {
        "url": "",
        "id": "sncf",
        "license": "",
        "name": ""
      }
    ]
  }
  </code></pre>