function createSkeletonWithRawAtlas(rawData) {
          new TextureAtlas(rawData, adapter, function (spineAtlas) {
            if (spineAtlas) {
              self.parseData(resource, parser, spineAtlas, dataToParse);
            }
            next();
          });
        }
use a bit of hackery to load the atlas file, here we assume that the .json, .atlas and .png files
that correspond to the spine file are in the same base URL and that the .json and .atlas files
have the same name