title: Remove Seaborn barplot legend title
body: <p>I use seaborn to plot a grouped bar plot as in <a href="https://seaborn.pydata.org/examples/factorplot_bars.html" rel="noreferrer">https://seaborn.pydata.org/examples/factorplot_bars.html</a></p>
  
  <p>Giving me:
  <a href="https://seaborn.pydata.org/_images/factorplot_bars.png" rel="noreferrer">https://seaborn.pydata.org/_images/factorplot_bars.png</a></p>
  
  <p>there is a title (sex) on the legend which I would like to remove. </p>
  
  <p>How could I achieve that?</p>