title: Kivy: export_to_png() with an arbitrary scale
body: <p>Is there a way to export a widget to png with an arbitrary scale in Kivy?</p>
  
  <p>As far as I understand, now by default the scale of an exported image is 1:1 relative to size of widget that I see on the screen.</p>
  
  <p>But what if I want to export to 1:10 (and get an image 10 times larger)?</p>
  
  <p>Interested in any ideas how this can be done.</p>