title: No handler for type [text] declared on field [title] (python elasticsearch
body: <p>all.
  The python elasticsearch version I used is</p>
  
  <pre><code>import elasticsearch
  print elasticsearch.__version__
  (5, 0, 1)
  </code></pre>
  
  <p>the mappings is </p>
  
  <pre><code>request_body = {
      'mappings':{
          'post': {
              'properties': {
                  'title': {
                      'type': 'text',
                  }
              }
          }
      }
  }
  </code></pre>
  
  <p>The error is :</p>
  
  <blockquote>
    <p>{u'status': 400, u'error': {u'caused_by': {u'reason': u'No handler for
    type [text] declared on field [title]', u'type':
    u'mapper_parsing_exception'}, u'root_cause': [{u'reason': u'No handler
    for type [text] declared on field [title]', u'type':
    u'mapper_parsing_exception'}], u'type': u'mapper_parsing_exception',
    u'reason': u'Failed to parse mapping [post]: No handler for type
    [text] declared on field [title]'}}</p>
  </blockquote>
  
  <p>Why es 5.0 can not recognize the "text" type? What's wrong with my setup?
  Thanks a lot!</p>