enable https quick steps
https://certbot.eff.org/lets-encrypt/ubuntutrusty-apache
(tested on ubuntu 14.04 trusty)
sudo apt-get update
sudo apt-get install software-properties-common
sudo add-apt-repository ppa:certbot/certbot
sudo apt-get update
sudo apt-get install python-certbot-apache
sudo letsencrypt certonly -a webroot --webroot-path=/var/www/html -d www.your_domain.com
sudo certbot --apache