Setting timeout to a default of False in get_auth()
results in a requests timeout of 0.0 in keystoneclient,
which causes a connection failure.
This bug will cause func tests to not run when using
keystoneauth.
Added unit tests to verify correct default timeout is set
in get_auth().
Drive-by: remove what seems like a stale TODO comment
Change-Id: I17c781ce160a682b1768d315422ade0cdd2df198