Use double rather than float

sky/examples/touch-demo.sky

Index: sky/examples/touch-demo.sky
diff --git a/sky/examples/touch-demo.sky b/sky/examples/touch-demo.sky
index 7644d0c403b4c6b9acae67d86b90ac0ab9ca056d..43f99d2d413fbc224b44ae3723d80b352ec6a2da 100644
--- a/sky/examples/touch-demo.sky
+++ b/sky/examples/touch-demo.sky
@@ -47,7 +47,7 @@ void stopDots(event) {
 }
 
 void runToTheCenter(event) {
-  float radius = (5 + (95 * event.pressure));
+  double radius = (5 + (95 * event.pressure));
   Element dot = whichDot(event);
   dot.style["transform"] = "translate(${event.x-radius}px,${event.y-radius}px)";
   dot.style["width"] = "${2 * radius}px";