feat(reorganize): export Notification from rxjs

spec/index-spec.ts

@@ -139,4 +139,12 @@ describe('index', () => {
     expect(index.queueScheduler).to.exist;
     expect(index.animationFrameScheduler).to.exist;
   });
+
+  it('should export Subscription', () => {
+    expect(index.Subscription).to.exist;
+  });
+
+  it('should export Notification', () => {
+    expect(index.Notification).to.exist;
+  });
 });

src/index.ts

@@ -134,8 +134,13 @@ export { BehaviorSubject } from './BehaviorSubject';
 export { ReplaySubject } from './ReplaySubject';
 
 /* Schedulers */
-
 export { asap as asapScheduler } from './scheduler/asap';
 export { async as asyncScheduler } from './scheduler/async';
 export { queue as queueScheduler } from './scheduler/queue';
 export { animationFrame as animationFrameScheduler } from './scheduler/animationFrame';
+
+/* Subscription */
+export { Subscription } from './Subscription';
+
+/* Notification */
+export { Notification } from './Notification';