Read the config from CONFIG_PATH(Default: ~/.grabflickr.conf)
    This will prompt for API key and secret if it not exists.
    After, it sets the global variable `api_key` and `api_secret`.

def read_config():
    """Read the config from CONFIG_PATH(Default: ~/.grabflickr.conf)
    This will prompt for API key and secret if it not exists.
    After, it sets the global variable `api_key` and `api_secret`.
    """
    parser = SafeConfigParser()
    parser.read(CONFIG_PATH)
    if not parser.has_section('flickr'):
        logger.info('Seems you don\'t set API key, please enter the following informations: ')
        enter_api_key(parser)
    global api_key, api_secret
    api_key = parser.get('flickr', 'API_KEY')
    api_secret = parser.get('flickr', 'API_SECRET')