Localhost
https://www.digitalocean.com/community/tutorials/how-to-create-a-ssl-certificate-on-apache-for-ubuntu-14-04
Produção e free
https://www.digitalocean.com/community/tutorials/how-to-set-up-let-s-encrypt-certificates-for-multiple-apache-virtual-hosts-on-ubuntu-16-04
e removendo: https://community.letsencrypt.org/t/correct-way-to-completely-remove-issued-certificate-s-for-a-domain/7409/12
https://www.jeffgeerling.com/blog/2016/remove-single-certbot-letsencrypt-certificate-server