python错误： setuptools pkg_resources pip wheel failed with error code 2
apt-get purge python-virtualenv python3-virtualenv virtualenv
pip install virtualenv
// run certbot-auto with --no-bootstrap
参考：
https://segmentfault.com/a/1190000010693933
http://www.fengzifz.com/2018/11/15/Ubuntu-18-letsencrypt/搜索更多相关主题的帖子:
python linux certbot letscrypt SSL
