title: Jenkins Pipeline currentBuild.changeSets and retrieving emails per repository
body: <p>I have a Jenkins pipeline job, that check outs three repositories.</p>
  <p>When the build fails, depending on where it fails, I want to send emails to the developers which caused the last commits/changes.</p>
  <p>I can retrieve the authors full names with this:</p>
  <pre class="lang-java prettyprint-override"><code>def changeSet = script.currentBuild.changeSets[0];
  Set authors = [];
  if (changeSet != null) {
      for (change in changeSet.items) {
          authors.add(change.author.fullName)
      }
  }
  </code></pre>
  <p>But I cannot figure out:</p>
  <ol>
  <li>How can I get the authors email?</li>
  <li>How can I distinguish the authors for different repositories?</li>
  </ol>