title: Delete empty directory from Jupyter notebook error
body: <p>I am trying to delete an empty directory in Jupyter notebook. 
  When I select the folder and click Delete, an error message pops up saying:
  'A directory must be empty before being deleted.'</p>
  
  <p>There are no files or folders in the directory and it is empty.</p>
  
  <p>Any advice on how to delete it?</p>
  
  <p>Thank you!</p>