title: Elasticsearch count in groups by date range
body: <p>I have documents like this:</p>
  
  <pre><code>{
  body: 'some text',
  read_date: '2017-12-22T10:19:40.223000'
  }
  </code></pre>
  
  <p>Is there a way to query count of documents published in last 10 days group by date? For example:   </p>
  
  <pre><code>2017-12-22, 150  
  2017-12-21, 79  
  2017-12-20, 111  
  2017-12-19, 27  
  2017-12-18, 100  
  </code></pre>