lib/utils/downloadTemplateFromRepo.js/validateUrl
function validateUrl(url, hostname, service, owner, repo) {
  // validate if given url is a valid url
  if (url.hostname !== hostname || !owner || !repo) {
    const errorMessage = `The URL must be a valid ${service} URL in the following format: https://${hostname}/serverless/serverless`;
    throw new ServerlessError(errorMessage);
  }
}