Bump savanna client used for tests to >= 0.4.0
Bump savanna client used for tests to >= 0.4.0

It's currently used only by integration tests.

Change-Id: If75e44e7a18aea777f738a3d9bd354763b54e711

openstack/sahara-tests,openstack/sahara-tests,openstack/sahara-scenario,esikachev/sahara-tests,openstack/sahara-tests,openstack/sahara-scenario,esikachev/sahara-tests,openstack/sahara-scenario,openstack/sahara-tests,esikachev/sahara-tests