code: function convertPr (ghPr) {
    return {
      number: ghPr.number,
      description: ghPr.body,
      url: ghPr.html_url,
      headSha: ghPr.head.sha
    }
  }
docs: Convert a GitHub PR to a PR representation
  @param {GitHubPullRequest} ghPr - the API response from a GitHub API looking for a PR
  @returns {PullRequest} a pull request in standard format