add song to show

src/app/modules/shows/services/show-song.service.spec.ts

@@ -0,0 +1,16 @@
+import {TestBed} from '@angular/core/testing';
+
+import {ShowSongService} from './show-song.service';
+
+describe('ShowSongService', () => {
+  let service: ShowSongService;
+
+  beforeEach(() => {
+    TestBed.configureTestingModule({});
+    service = TestBed.inject(ShowSongService);
+  });
+
+  it('should be created', () => {
+    expect(service).toBeTruthy();
+  });
+});