This commit allows this plugin to be run in parallel with other devstack plugins
like glusterfs, ceph, etc. This is needed to allow gate jobs that test
multibackend features.
Change-Id: I79c5ee753607953ffad7e78b96ffea506d84fc21
The Cinder NFS backend doesn't yet support snapshot, clone
or backup operations, so they should be disabled when
running Tempest.
We also have to explicitly disable the image cache in
cinder because that relies on volume cloning which the NFS
volume backend doesn't support.
Depends-On: I5ad578a78d6cfd4186a8230ad472d4a7b92445c9
Change-Id: I8fb421276005f9ba9cbc6c55ba8b6089349fdb69