Add filter support for `network ls` to hide predefined network,
then user can use "docker network rm `docker network ls -f type=custom`"
to delete a bundle of userdefined networks.
Signed-off-by: Zhang Wei <zhangwei555@huawei.com>
It makes the behavior completely consistent across commands.
It adds tests to check that execution stops when an element is not
found.
Signed-off-by: David Calavera <david.calavera@gmail.com>