使用Digital Ocean上网

参考：

【1】How To Use SSH Keys with PuTTY on DigitalOcean Droplets (Windows users) https://www.digitalocean.com/community/tutorials/how-to-use-ssh-keys-with-putty-on-digitalocean-droplets-windows-users

【2】使用 DigitalOcean 和 shadowsocks 来科学上网 http://jerryzou.com/posts/shadowsocks-and-digitalocean/

【3】在DigitalOcean上配置Shadowsocks实现IPV4/IPV6翻墙 https://xmfbit.github.io/2017/02/08/digitalocean-shadowsocks/