https://ipaddress.com/website/github.com
https://ipaddress.com/website/github.global.ssl.fastly.net#ipinfo
https://ipaddress.com/website/assets-cdn.github.com
修改host文件
刷新dns，mac需要权限，win在shell cmd里执行
sudo killall -HUP mDNSResponder;say DNS cache has been flushed
克隆成功
