[Grenade] Do not run tempest tests
[Grenade] Do not run tempest tests

Since tempest is not used in manila grenade logic skip run of its
tests.

Change-Id: I6c45448ec286fe6c365b4e9edcce56501e5c87bd
Closes-Bug: #1650482

vponomaryov/manila,openstack/manila,bswartz/manila,openstack/manila,vponomaryov/manila,bswartz/manila