Add test for multi-SP logout
    
    Create an additional SP, log into one, fetch the other and
    the client is now logged into both. Log out of the first one
    and the client is logged out of both.
    
    https://fedorahosted.org/ipsilon/ticket/58
    
    Signed-off-by: Rob Crittenden <rcritten@redhat.com>
    Reviewed-by: Nathan Kinder <nkinder@redhat.com>