7e4ca449a0
As the first step towards removing rpc_backend, we need all of the test fixtures to stop setting/using it via ConfFixture.transport_driver. Add ConfFixture.transport_url, and move the tests over to setting it rather than transport_driver. Partial-Bug: #1712399 Change-Id: I6e2ae2b511fdc52790d5755a9aecaf2f427ab706