Add unit test for TestServerList to test --long option.
Add unit test for TestServerList to test --long option.

In two steps:
1. Setup all necessary attributes of a server in setUp(), including
   the ones that are not faked in FaseServer by default.
2. Run a similar process with no option test case.

The future plan is to move all these attributes to FakeServer.
But it will cause some other changes which has nothing to do with
this patch. So leave this job to do later.

Change-Id: I1134812a0ea146ef737b0f0ffbef8ca23684accd
Implements: blueprint osc-unit-test-framework-improvement

dtroyer/python-openstackclient,dtroyer/python-openstackclient,redhat-openstack/python-openstackclient,redhat-openstack/python-openstackclient,openstack/python-openstackclient,openstack/python-openstackclient