ECOM-5776

Ready for deploying Mongo 3.2

Feanil/ecom worker 16.04

Add a flag to easily turn on/off the logging.

Feanil/update aws cli

This is the credentials app. Not discovery.

Feanil/credentials 16.04

motd.tail support for Xenial

Add config for Zendesk custom fields

New base image that disables daily/boot apt updates

The security role was not run on the base image, meaning that
these tasks were not disabled.  This was causing sandbox builds to fail
if a systemd timer task was also running (which is a bit
nondeterministic to predict unfortunately).

DEVOPS-5273

Fix booleans so Mongo only listens on localhost

Move to 16.04 base sandbox images.

Don't use virtio for dogwood or eucalyptus boxes

Fix spelling in the pull request template

Pull leeway out into var

Add a version override here so it's easy to update.

Analytics-Api will generally need to be built from a tag so that Insights
tests can run with that version.  Adding this line here to make it easier
to update when that process occurs.

Change migrate --list to showmigrations in pre_supervisor_checks

Django removed `migrate --list` in version 1.10 and added showmigrations in 1.8.
I left LMS, CMS, and xqueue alone because they have their own special way of
checking migrations.

ECOM-5936

become true for managing users and groups