backup = async function backup(options = {}) {
    // do not create backup if disabled in config (this is intended for large customers who will OOM node)
    if (config.get('disableJSBackups')) {
        logging.info('Database backup is disabled in Ghost config');
        return null;
    }

    logging.info('Creating database backup');

    const filename = await exporter.fileName(options);
    const data = await exporter.doExport(options);

    const filePath = await writeExportFile({
        data,
        filename
    });

    logging.info(`Database backup written to ${filePath}`);
    return filePath;
}
Does an export, and stores this in a local file

@param {Object} options
@returns {Promise<String> | null}