fedpkg update --suggest-logout option added
    
    Option --suggest-logout was not implemented although it
    is supported by Bodhi. This commit adds this option.
    
    Jira: RHELCMP-8704
    Fixes: https://pagure.io/fedpkg/issue/472
    
    Signed-off-by: Dominik Rumian <drumian@redhat.com>