title: bqplot: ipython widgets not being rendered
body: <p>I am trying to use <a href="https://github.com/bloomberg/bqplot" rel="nofollow noreferrer"><strong>bqplot</strong></a> to plot some graphs in jupyter notebook along with some ipywidgets. I want to render the widgets horizontally adjacent to my plot as discussed in <a href="https://github.com/ipython/ipywidgets/issues/1067" rel="nofollow noreferrer">this issue</a>, but I cannot get the widgets to show up in my jupyter notebook. </p>
  
  <p>My code is as follows -</p>
  
  <pre><code>from bqplot import pyplot as plt
  import ipywidgets as widgets
  from pandas import DataFrame
  
  class AdderDOEProblem_PlotUtils:
      def __init__(self, parseutils):
          self.data = DataFrame({'timestamps': parseutils.getTimestampValues(),
                              'Adder.sum': parseutils.getValues('Adder.sum'),
                              'Adder.a': parseutils.getValues('desvar_a.a'),
                              'Adder.b': parseutils.getValues('desvar_b.b')})
          # step size
          self.Adder_a__step = 0.1
          self.Adder_b__step = 0.1
  
          # axes configuration
          x_axis_values = self.data['Adder.a']
          y_axis_values = self.data['Adder.sum']
  
          self.fig = plt.figure(title='AdderDOEProblem')
          self.p = plt.plot(x_axis_values, y_axis_values)
  
          w_a_slider = widgets.FloatSlider(value=0, min=0, max=1, step=self.Adder_a__step, description='Adder.a')
          w_b_slider = widgets.FloatSlider(value=0, min=0, max=1, step=self.Adder_b__step, description='Adder.b')
          self.widgets_list = [w_a_slider, w_b_slider]
  
      def update (self, change):
          # Placeholder logic for testing 
          self.p.y = [i+1 for i in self.p.y]
  
      def plot (self):
          plt.show()
          for w in self.widgets_list:
              w.observe(self.update, 'value')
          self.update(None)
          widgets.HBox([widgets.VBox(self.widgets_list), self.fig])
  </code></pre>
  
  <p>When I run it in the notebook, I get the following output -</p>
  
  <p><a href="https://i.stack.imgur.com/4iaxz.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/4iaxz.png" alt="jupyter notebook output"></a></p>
  
  <p>I have tried the following command as suggested in many of the threads (but with no luck) -</p>
  
  <pre><code>jupyter nbextension enable --py widgetsnbextension
  </code></pre>
  
  <p>What am I missing?</p>
  
  <p>P.S. The versions of the packages are as follows -<br>
  jupyter - 1.0.0<br>
  ipython - 5.1.0<br>
  ipywidgets - 5.2.2<br>
  bqplot - 0.8.4   </p>