title: async await with elasticsearch search/scroll
body: <p>I'm using <code>await</code> as part of my search but as its +30000 items I have to use <code>scroll</code>. </p>
  
  <p>The issue is that the initial part of the search is complete before the <code>scroll</code> is so the <code>await</code> fires and function carries on. what should I be doing to stop this?</p>
  
  <pre><code>var allTitles = [];
  try {
      await client.search({
          index: 'myindex',
          scroll: '30s',
          source: ['title'], 
          q: 'title:test'
      }, function getMoreUntilDone(error, response) { 
          response.hits.hits.forEach(function (hit) {
              allTitles.push(hit._source.title);
      });
      if (response.hits.total &gt; allTitles.length) {
          client.scroll({
              scrollId: response._scroll_id,
              scroll: '30s'
          }, getMoreUntilDone);
      } else {
          console.log('every "test" title', allTitles);
         }
      });
  } catch (err) {
      console.log(err)
  }
  </code></pre>