Remove Sky tests that we don't intend to port to the new world

sky/tests/events/gesture-events.sky

-<sky>
-<import src="../resources/chai.sky" />
-<import src="../resources/mocha.sky" />
-<div id="target" />
-<script>
-describe("Gesture events", function() {
-  it("should be creatable", function() {
-    var event = new GestureEvent("tap");
-    assert.ok(event);
-  });
-
-  it("should be dispatchable", function() {
-    var div = document.getElementById("target");
-    var marker = false;
-    div.addEventListener("tap", function(event) {
-      assert.instanceOf(event, GestureEvent);
-      marker = true;
-    });
-    div.dispatchEvent(new GestureEvent("tap"));
-    assert.isTrue(marker);
-  });
-});
-</script>
-</sky>