Remove container-update.py
Remove container-update.py

This script is not packaged and does not appear to be used. The code
is specific to docker, a platform we no longer support (replaced by
podman).

Change-Id: Ic198802a75ceda79e0593cf551317e3bdedd2097
Signed-off-by: Luke Short <75ade22b5a2100772de069dd66aee23213a7adc0@gmail.com>

openstack/tripleo-common,openstack/tripleo-common