Our test container does not support an orchestrator to pre configure
the ".nfs" configuration pool for us. This is something that rook and
cephadm are expected to do before exports are created, etc.
So we support creating a minimal "mock" configuration in rados.
This option can be toggled on and off via the GO_CEPH_TEST_MOCK_NFS
env var. Turning it off can be useful if you want to run the live
suite against a "real" ceph cluster.
Signed-off-by: John Mulligan <jmulligan@redhat.com>