Merge pull request #59 from Brightspace/dbatiste/use-core-requestIdle…

…Callback

Use requestIdleCallback from core.

requestIdleCallback.js

@@ -1,15 +1 @@
-window.requestIdleCallback = window.requestIdleCallback || function(cb) {
-	var start = Date.now();
-	return setTimeout(function() {
-		cb({
-			didTimeout: false,
-			timeRemaining: function() {
-				return Math.max(0, 50 - (Date.now() - start));
-			}
-		});
-	}, 1);
-};
-
-window.cancelIdleCallback = window.cancelIdleCallback || function(id) {
-	clearTimeout(id);
-};
+import '@brightspace-ui/core/helpers/requestIdleCallback.js';