title: Title for matplotlib legend
body: <p>I know it seems fairly redundant to have a title for a legend, but is it possible using matplotlib?</p>
  
  <p>Here's a snippet of the code I have:</p>
  
  <pre><code>import matplotlib.patches as mpatches
  import matplotlib.pyplot as plt
  
  one = mpatches.Patch(facecolor='#f3f300', label='label1', linewidth = 0.5, edgecolor = 'black')
  two = mpatches.Patch(facecolor='#ff9700', label = 'label2', linewidth = 0.5, edgecolor = 'black')
  three = mpatches.Patch(facecolor='#ff0000', label = 'label3', linewidth = 0.5, edgecolor = 'black')
  
  legend = plt.legend(handles=[one, two, three], loc = 4, fontsize = 'small', fancybox = True)
  
  frame = legend.get_frame() #sets up for color, edge, and transparency
  frame.set_facecolor('#b4aeae') #color of legend
  frame.set_edgecolor('black') #edge color of legend
  frame.set_alpha(1) #deals with transparency
  plt.show()
  </code></pre>
  
  <p>I would want the title of the legend above label1. For reference, this is the output:
  <a href="https://i.stack.imgur.com/qK0hz.png" rel="noreferrer"><img src="https://i.stack.imgur.com/qK0hz.png" alt="Showing legend"></a></p>