title: matplotlib legend circle markers
body: <p>I'm making a legend for a scatter plot using a proxy artists (http://matplotlib.sourceforge.net/users/legend_guide.html#using-proxy-artist) and attempting to make circle-shaped markers.</p>
  
  <p>This is my code:</p>
  
  <pre><code>legend([Circle((0,0), fc='g')], ["Green Circle"])
  </code></pre>
  
  <p>But when I plot it, the legend doesn't have a circle and instead displays a rectangle...</p>
  
  <p>How do I get the legend to have circle markers?</p>