example: 这将获取所有的版本
https://api.github.com/repos/januwA/flutter_anime_app/releases最新版本:
https://api.github.com/repos/januwA/flutter_anime_app/releases/latest下载最新的包
https://api.github.com/repos/januwA/flutter_anime_app/releases/latest // 获取下载地址: r.assets[0].browser_download_url