Ignore files in a cloned repository
    
    Git will ignore automatically generated files. Ignored patterns can be
    specified in rhpkg/fedpkg config. Patterns are applied in
    '.git/info/exclude' file only when repository is cloned. And changes are
    valid only for local repository.
    
    JIRA: COMPOSE-2794
    Fixes: #355
    
    Signed-off-by: Ondrej Nosek <onosek@redhat.com>