Updated openstack/openstack
Project: openstack/tempest  b74fb27895ce1808ff0c414b8b4f61b9c51cf697

Add os-networks JSON client for tempest

There is no client for the os-networks API.
Scenario tests do use that API, and migrating them to tempest clients
triggered the need for this client to exists.
Scenario tests only run with JSON, so only providing JSON implementation.

Partially implements bp:tempest-client-scenarios

Change-Id: I85da97a98fc558af14e2a9fc019b6e712653ecf2