title: how to get on hover animation of pygal graphs in ipython on mac osx
body: <p>I have just started using pygal in ipython after installing CairoSVG with pip and Cairo with homebrew. </p>
  
  <p>The graphs render but when I hover over them there is no interactivity (displaying the frequency for a single bar on a bar graph for example)?</p>
  
  <p>What do I need to install to achieve the same rollover/hover functionality that can be seen in the Pygal Documentation?</p>
  
  <p><a href="http://www.pygal.org/en/latest/documentation/first_steps.html" rel="nofollow">http://www.pygal.org/en/latest/documentation/first_steps.html</a></p>
  
  <p>For example when you click on a legend item on a graph, the legend item is greyed out and hidden. Clicking the legend item again makes it return. When I create the sample First Steps code in Ipython and click on a legend item it doesn't disappear.</p>