Fix Salt's yaml-ification of on/off, and otherwise normalize the on/off
    values to be used in writing the options file

def _normalize(val):
    '''
    Fix Salt's yaml-ification of on/off, and otherwise normalize the on/off
    values to be used in writing the options file
    '''
    if isinstance(val, bool):
        return 'on' if val else 'off'
    return six.text_type(val).lower()