Add script to create tripleo-admin on deployed servers
Add script to create tripleo-admin on deployed servers

When using deployed servers, we want to create a standard
tripleo-admin user for Mistral's ssh tasks (e.g. running Ansible on
overcloud). This script wraps the respective Mistral workflow.

Change-Id: I2de698b4aae07f74569243a9e7c1c56eb578e700
Related-Bug: #1708180
Depends-On: Ibe8e54f7b38d8c6c8d944d2b13f0eed004c34c4c

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