Convert shim to Typescript (#32)

ext/src/shim/cast/classes/Timeout.ts

@@ -0,0 +1,10 @@
+"use strict";
+
+import * as timeouts from "../../timeout";
+
+// https://developers.google.com/cast/docs/reference/chrome/chrome.cast.Timeout
+export default class Timeout {
+    constructor () {
+        Object.assign(this, timeouts);
+    }
+};