Rename kolla_ansible to kolla_toolbox

This change is needed for clarity. We have a kolla-ansible script.
We have a kolla-mesos repo. We plan to have a kolla-ansible repo.
Already we have had far too much confusion about whether we are
talking about the container or the project. Naming this kolla-toolbox
eliminates all of that confusion and its probably a bit more accurate
of a name too.

Closes-Bug: #1541053
Change-Id: I8fd1f49d5a22b36ede5b10f46b9fe02ddda9007e