/* istanbul ignore next
function downloadString(url) {
  return new Promise((resolve, reject) => {
    request({
      url,
      // We want to force Cloudfront to serve us the latest file.
      headers: {
        'Accept-Encoding': 'gzip, deflate',
      },
    }, (error, response, body) => {
      if (!error && response.statusCode === 200) {
        resolve(body);
      } else {
        reject(error || response.statusCode);
      }
    });
  });
}