参考
https://www.digitalocean.com/community/tutorials/how-to-add-and-delete-users-on-ubuntu-16-04
切换成 root
sudo -i
创建一个用户
adduser newuser
设置密码
passwd newuser
给新用户添加sudo权限
usermod -aG wheel newuser
删除用户
deluser newuser
删除用户家目录
deluser --remove-home newuser