See https://docs.ansible.com/ansible/playbooks_lookups.html

The ownCloud configuration file does not get touched.  The virtual host
configuration is modified by sovereign but can be updated in place and
Apache restarted.

This is done to suppress warnings from ansible-lint.

Depending on when the client is run, there are no certificates to
update.  By default, the client runs in interactive mode and wants to
notify the user of this.  This causes Ansible to hang waiting for an
acknowledgement that will never come.  Adding the non-interactive flag
fixes this.

as per discussion in https://github.com/sovereign/sovereign/pull/504

The ``sudo`` and ``sudo_user`` directives are replaced with ``become``
and ``become_user`` in Ansible 1.9.

The installer automatically updates itself, which registers as a change
in the git repo.  To maintain idempotency of the task list, the repo
download must be forced.

- Remove unnecessary dependencies
- Clean up postgresql server setup
- Install from official package repository
- Expect package installer to enable modules that are needed
- Update virtual host config with owncloud 8.2 configuration
- Update post-deploy instructions

Fix Apache's configuration for version 2.4.8 and above.  See
https://community.letsencrypt.org/t/untrusted-on-mobile-newbe/7903

Don't copy the LE certificates.  Instead use the ssl-cert group to
manage access to the LE certificates directly.  See
https://github.com/letsencrypt/letsencrypt/issues/1425 for a request to
have the LE client do this itself.