Update README with test running instructions.
Update README with test running instructions.

Change-Id: I772b8fda5abdd07bc212a5fc7358e4b712425cd2

emonty/oslo-packaging,openstack-dev/pbr,JioCloud/pbr,citrix-openstack-build/pbr,redhat-openstack/pbr,WiFast/pbr,JioCloud/pbr,openstack-dev/pbr,varunarya10/pbr,klmitch/pbr,citrix-openstack-build/pbr,openstack-dev/pbr,varunarya10/pbr,redhat-openstack/pbr,citrix-openstack-build/pbr,WiFast/pbr,klmitch/pbr,emonty/oslo-packaging