Cumulus Linux Ansible demo

Demo of using Ansible to provision a 2-spine/2-leaf CLOS topology, using OSFP unnumbered links to implement ECMP; also demos the Cumulus-authored "Prescriptive Topology Manager" software which verifies actual inter-switch cabling to a wiring plan file.

*** This demo was authored by Cumulus Networks, and was performed on their "Customer Workbench" lab environment ***