Add test for per-SP allowed and mapping attributes
    
    This buidls up a specific global mapping and allowed attributes then
    creates an SP-specific configuration which differs enough to confirm
    that it is in fact overriding the default. It finishes by removing the
    per-SP configuration and ensuring that it falls back to the IdP-default.
    
    https://fedorahosted.org/ipsilon/ticket/25
    
    Signed-off-by: Rob Crittenden <rcritten@redhat.com>
    Reviewed-by: Simo Sorce <simo@redhat.com>