Method downloadFile

/**
 * Downloads the Update file
 *
 * @param   string  $url  URL to update file
 *
 * @return boolean | string
 *
 * @since 4.0.0
 */
public function downloadFile($url)
{
    $file = InstallerHelper::downloadPackage($url);
    if (!$file) {
        return false;
    }
    return $file;
}