changed build tag in rados/ioctx_nautilus.go and
rados/ioctx_nautilus_test.go in a way such that the
functions in these files are built for nautilus only.
Signed-off-by: Mudit Agarwal <muagarwa@redhat.com>
Now, we don't support ceph versions < nautilus this function
can move to a generic file so that nautilus specific functions
can be written here. Moved GetNamespace() and the corresponding
test function.
Signed-off-by: Mudit Agarwal <muagarwa@redhat.com>