title: Adding a y-axis label to secondary y-axis in matplotlib
body: <p>I can add a y label to the left y-axis using <code>plt.ylabel</code>, but how can I add it to the secondary y-axis?</p>
  
  <pre><code>table = sql.read_frame(query,connection)
  
  table[0].plot(color=colors[0],ylim=(0,100))
  table[1].plot(secondary_y=True,color=colors[1])
  plt.ylabel('$')
  </code></pre>