code: public function rename($file, $new_file)
      {
          $key = trim($file);
          $url = "{$this->QINIU_RS_HOST}/move/" . self::qiniuEncode("{$this->bucket}:{$key}") . '/' . self::qiniuEncode("{$this->bucket}:{$new_file}");
          trace($url);
          $accessToken = $this->accessToken($url);
          $response    = $this->request($url, 'POST', ['Authorization' => "QBox $accessToken"]);
          return $response;
      }
docs: 重命名单个文件