Fix data visualizer resizing (#930)

* Fix data visualizer resizing

Stops the visualizer from limiting the height of the display by creating a second, nested display area with its own set of scroll bars.

* Remove commented-out code

Author: lumos309

src/styles/_playground.scss

@@ -7,6 +7,4 @@
 
 .kineticjs-content {
   width: 100% !important;
-  height: 40vh !important; // 100% results in 0 height, 100vh is too big.
-  overflow: scroll;
 }