fix driver spec test

Signed-off-by: Hiroshi Miura <miurahr@linux.com>
spec: driver: add stub for pool and volume
clean unused stub

Signed-off-by: Hiroshi Miura <miurahr@linux.com>
fix exception on join

Signed-off-by: Hiroshi Miura <miurahr@linux.com>
driver: explict method call

Signed-off-by: Hiroshi Miura <miurahr@linux.com>
update test box.xml

Signed-off-by: Hiroshi Miura <miurahr@linux.com>
add spec test for driver

Signed-off-by: Hiroshi Miura <miurahr@linux.com>