Update the group_vars and globals docuementation as well.
Change-Id: I3ffd49b8d99667425596a2753845767a62e05bf1
Partially-Implements: blueprint kolla-docker-module
The upstream docker module in control of Ansible has proven to be a
major breaking point for Kolla. It is the reason we have a cap on
Docker of 1.8.2. They have stated no support for the Docker registry
v1 moving forward. We have to wait for a patch to land and then
upgrade to the latest Ansible version to take advantage of a new
Docker feature. Doing that is slow and it is not always possible to
upgrade if there are other breaking changes (aka ansible 2.0).
For these reasons we can build our own Docker module.
Partially-Implements: blueprint kolla-docker-module
Change-Id: I2ca57010c45710635cfe80ff23a2a5e2edabee57
