calculate default duration based on distance instead of start position

Author: ditam

elevator.js

@@ -111,7 +111,7 @@ var Elevator = function(options) {
 
         // No custom duration set, so we travel at pixels per millisecond. (0.75px per ms)
         if( !customDuration ) {
-            duration = (startPosition * 1.5);
+            duration = ( Math.abs(endPosition - startPosition) * 1.5);
         }
 
         requestAnimationFrame( animateLoop );