remove tempest pin
remove tempest pin

Change [1] removed the tempest pin from the
pre test hook in manila proper.

Remove it here as well.

Closes-Bug: #1711815

[1] Ia402fb79e1de5c9925f575d635b9928475095f86

Change-Id: I2a6e1854718df272eb40d68cbe41d9ddfb962b71

openstack/devstack-plugin-ceph,ajarr/devstack-plugin-ceph