Drag on the canvas to rotate the cube.
Resources:

• http://codentronix.com/2011/04/27/first-experiment-with-html5-a-wireframe-cube/
• http://stackoverflow.com/questions/38392640/how-to-add-ondrag-mouse-event-in-this-example
• https://developer.mozilla.org/en-US/docs/Web/API/window/requestAnimationFrame
• https://css-tricks.com/using-requestanimationframe/