项目整体结构参考 aws， 如下

├── config···································· sdk 的配置文件
├── example··································· 应用案例
├── internal·································· 内部工具包，不被上层应用代码调用（仅提供给qilin）
├── qilin····································· qilin通用包，提供给上层应用编写客户端代码
│ ├── gerr·································· 通用错误包
│ ├── middlewave···························· 通用中间件
│ ├── transport····························· 网络协议相关
├── service···································上层业务应用服务的客户端代码