Adds nova snapshot to the controller node

Snapshot 'nova-controller_installed' will contain the following
packages

    1. nova-api
    2. nova-cert
    3. nova-conductor
    4. nova-consoleauth
    5. nova-novncproxy
    6. nova-scheduler
    7. python-novaclient

Installs and configures nova, configures keystone to authenticate with
nova.

This snapshot can be used to obtain stable running version of
controller node and can be used to revert back to this point in case
the students break the cluster.

Change-Id: I4c4d2ff51cd46e19ea9679f7f536d23ca0317bb0
Merge "Adds nova snapshot to the controller node"