FakeXXX classes in network don't need to fake any method,
except keys(). But keys() can be put in FakeResource since
it just returns all attributes in _info.
This patch moves removes all unnecessary fake methods code,
moves keys() method to FakeResource.
This patch also finds out some missing attributes in
network and router tests.
Change-Id: I799822c8715b9ac4f95b98f8350f196757d79d3e