Update standalone setup instructions
Update standalone setup instructions

1. Update "Standalone. Get Congress running all by itself."
   to reflect that the instructions are for installing alongside an
   existing OpenStack deployment. We may consider creating true
   standalone-install instructions in the future.
2. Update deprecated openstack command
   $ openstack service create congress --type "policy"
3. Update | awk "/ congress / { print \$2 }" to grab service id
4. Start Congress before configuring datasource drivers to avoid
   error:
Unable to establish connection to http://x.x.x.x:1789/v1/data-sources
5. Added bare congress.conf

Change-Id: I69f100f778f93f48a1b393a315ce8a0808ef771f

ramineni/my_congress,ramineni/my_congress,ramineni/my_congress,openstack/congress,openstack/congress,ramineni/my_congress