Make ServersViewBuilderTest DRYer.

Move detail and brief info about server from test methods to setUp()
to expected_detailed_server and expected_server respectively. Every
test modifies the particular fields in the variables to create
appropriate test environment.

Blueprint: nova-tests-code-duplication
Change-Id: I31bf6ed3c266da99c57b128c298cf7beae9a6db4
Merge "Make ServersViewBuilderTest DRYer."