Add messaging service

src/app/service/messaging.service.spec.ts

@@ -0,0 +1,12 @@
+import { TestBed } from '@angular/core/testing';
+
+import { MessagingService } from './messaging.service';
+
+describe('MessagingService', () => {
+  beforeEach(() => TestBed.configureTestingModule({}));
+
+  it('should be created', () => {
+    const service: MessagingService = TestBed.get(MessagingService);
+    expect(service).toBeTruthy();
+  });
+});