title: AttributeError: 'Search' object has no attribute 'execute_suggest'
body: <p>Here is my code:</p>
  
  <pre><code>class SearchSuggest(View):
      def get(self, request):
          key_words = request.GET.get('s', '')
          re_datas = []
          if key_words:
              s = ArticleType.search()
              s = s.suggest('my_suggest', key_words, completion={
                  "field": "suggest", "fuzzy": {
                  "fuzziness": 1
                  },
                  "size": 5
              })
              suggestions = s.execute_suggest()
              for match in suggestions.my_suggest[0].options:
                  source = match._source
                  re_datas.append(source["title"])
          return HttpResponse(json.dumps(re_datas),
  
      content_type="application/json") 
  </code></pre>
  
  <p>It's a piece of code in views in django.when I run this project.It raise:</p>
  
  <pre><code>File "/home/yixuan/PycharmProjects/Scrapy/LcvSearch/search/views.py", line 20, in get
  suggestions = s.execute_suggest()
  AttributeError: 'Search' object has no attribute 'execute_suggest'
  </code></pre>
  
  <p>I don't know where is error. I will appreciate it if you can solve it.</p>
  
  <p>my version is:</p>
  
  <ul>
  <li>elasticsearch-dsl==6.1.0 </li>
  <li>elasticsearch==6.2.0 </li>
  </ul>