detail:

• add test case for config route with non-existent service_id

• add test case for config route with non-existent upstream_id

• add test case for config route with upstream_id and service_id at the same time

• add test case for config route with correct service_id

• verify the route just configured

• add test case for config route with correct upstream_id

• verify the route just configured

For background and description, please see:

#607