Improve debugging possibilities for docker-puppet.py time handling
Improve debugging possibilities for docker-puppet.py time handling

We faced issue where on some environments docker-puppet.py picks up
/etc/hosts as modified, even though that shouldn't be the case (LP bug
1709689). On the last occasion we found the cause to be desynced time
on the host machine of a virtual setup, and subsequent NTP sync of
overcloud nodes (causing a 5 hour skip back in time) racing with
docker-puppet.py.

Still, more info to debug these kinds of issues would be nice to
have. Printing the timestamp of origin_of_time, saving it to a
persistent directory and making sure /etc/localtime is mounted into
docker-puppet containers should make finding the root cause on such
occasions easier.

Change-Id: I2ea197673b470379ead295058b6952cce3a69606
Closes-Bug: #1737954

openstack/tripleo-heat-templates,openstack/tripleo-heat-templates,dprince/tripleo-heat-templates,dprince/tripleo-heat-templates