title: Plotly/dash - Module 'dash_html_components' has no 'Div' member
body: <p>I would like run this code from plotly.<br>
  Before, I installed these modules:</p>
  
  <pre><code>pip install dash==0.21.1  # The core dash backend
  pip install dash-renderer==0.13.0  # The dash front-end
  pip install dash-html-components==0.11.0  # HTML components
  pip install dash-core-components==0.23.0  # Supercharged components
  pip install plotly --upgrade  # Latest Plotly graphing library
  </code></pre>
  
  <p>My code is:</p>
  
  <pre><code>import dash
  import dash_core_components as dcc
  import dash_html_components as html
  
  app = dash.Dash()
  
  app.layout = html.Div(children=[
      html.H1(children='Hello Dash'),
  
      html.Div(children='''
          Dash: A web application framework for Python.
      '''),
  
      dcc.Graph(
          id='example-graph',
          figure={
              'data': [
                  {'x': [1, 2, 3], 'y': [4, 1, 2], 'type': 'bar', 'name': 'SF'}, 
                  {'x': [1, 2, 3], 'y': [2, 4, 5], 'type': 'bar', 'name': u'Montréal'},
              ],
              'layout': {
                  'title': 'Dash Data Visualization'
              }
          }
      )
  ])
  
  if __name__ == '__main__':
      app.run_server(debug=True)
  </code></pre>
  
  <p>However it doesn't work et I don't understand why !
  Can you help me please ! Thanks</p>