title: ggplotly in R studio fail to show results in viewer
body: <p>I am trying to use the ggplotly to convert ggplot object and it returns nothing, just a blank viewer... Can anyone tell me why? Thanks in advance.</p>
  <pre><code>ggp = ggplot(data = mtcars, aes(cyl)) + geom_density(kernel = &quot;gaussian&quot;)
  ggplotly(ggp)
  </code></pre>