code: function buildUrlWithSign(appKey, appSecret, params /*, callback*/ ){
      // callback = typeof callback === 'function' ? callback : (options || function(){});
      params.appKey = appKey;
      params.timestamp = params.timestamp || Date.now();
      
      // 生成sign
      params.sign = genSign(querystring.stringify(params), appSecret);
  
      var urlQuery = querystring.stringify(params);
      return  ConfigUrl.URL_AUTOLOGIN + '?' + urlQuery;
  }
docs: 生成免登录URL
  
  @param {String} appKey `接口key`
  eparam {String} appSecret `接口密匙`
  @param {Object} params `如下`
  ```
  {
  {String} uid      `用户id （用not_login作为uid标记游客用户，详见 游客访问）`
  {Long}   credits    `用户积分余额`
  {String} redirect `回调url`
  {Long}   timestamp `1970-01-01开始的时间戳，毫秒为单位。`
  }
  ```