Currently client email is submitted via ssmtp (port 465).  This has been
deprecated for years.  The correct way to submit email is via
submission (port 587).

This patch adds port 587 as a second and the default way of submitting
email for delivery.  Port 465 remains open for backwards compatibility
with existing clients.

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.