Add support for automatic provisioning and renewal of HTTPS
certificates via LetsEncrypt.

Spec is available at:
https://etherpad.opendev.org/p/kolla-ansible-letsencrypt-https

Depends-On: https://review.opendev.org/c/openstack/kolla/+/887347


Co-Authored-By: Michal Arbet <michal.arbet@ultimum.io>
Implements: blueprint letsencrypt-https
Change-Id: I35317ea0343f0db74ddc0e587862e95408e9e106