title: geopandas legend_kwds seems to be ignored
body: <p>I have a geodataframe which I'm plotting from, code looks like this</p>
  
  <pre><code>ax = df.plot(column='cap',
               cmap='Oranges', figsize=(16, 9),
               linewidth=0.5,
               edgecolor='black',
               facecolor='red',
               legend=True,
               legend_kwds={'frameon': True, 'loc': 'center left',
                            'title': 'My legend Title', 'fontsize': 24}
               )
  </code></pre>
  
  <p>I am trying to increase the size of the legend markers and played around with the legend_kwds, however it's always fixed at the right side of the plot, it doesn't matter what I pass in the dict.</p>
  
  <p>What am I missing?</p>
  
  <p>Thanks!</p>