https://certbot.eff.org/lets-encrypt/ubuntuxenial-apache
- sudo apt-get update
- sudo apt-get install software-properties-common
- sudo add-apt-repository universe
- sudo add-apt-repository ppa:certbot/certbot
- sudo apt-get update
sudo apt-get install certbot python-certbot-apache
sudo certbot --apache
sudo certbot renew --dry-run