Update the UI test running documentation
Update the UI test running documentation

The UI test section otdated and incomplete.
This commit updates docs with up to date instructions

Change-Id: I42563f76fbee8af3b7a45fb369de57dfd50d1363

DavidPurcell/murano_temp,DavidPurcell/murano_temp,openstack/murano,DavidPurcell/murano_temp,openstack/murano,DavidPurcell/murano_temp