17f2f1c tests: Add a getpwnam-by-UPN test

Authored and Committed by jhrozek 8 years ago
    tests: Add a getpwnam-by-UPN test
    
    Reviewed-by: Pavel Reichl <preichl@redhat.com>
    (cherry picked from commit 84a4c4fcc93b3dcc70604817a05f7943606ff596)