title: gridExtra 2.0.0 change title size
body: <p>I know that gridExtra has been updated. As a result, I'm left wondering how to change title sizes. This no longer works</p>
  
  <pre><code>   grid.arrange(a, b, c, d,ncol=2, 
        nrow=2, main=textGrob("Title", gp=gpar(fontsize=15,font=8)))
  </code></pre>
  
  <p>That no longer works, the option for main has been changed to top but I can't figure out the textGrob features to alter the font size). Any clues? Thanks</p>