feat(sandbox): example of pubnub as a provider in notification service

MIGRATION CHANGE:
migration-20210716062747- notification migration
migration-20210501132806- notification migration

gh-208

sandbox/pubnub-example/src/__tests__/acceptance/home-page.acceptance.ts

@@ -0,0 +1,31 @@
+import {Client} from '@loopback/testlab';
+import {PubnubExampleApplication} from '../..';
+import {setupApplication} from './test-helper';
+
+describe('HomePage', () => {
+  let app: PubnubExampleApplication;
+  let client: Client;
+
+  before('setupApplication', async () => {
+    ({app, client} = await setupApplication());
+  });
+
+  after(async () => {
+    await app.stop();
+  });
+
+  it('exposes a default home page', async () => {
+    await client
+      .get('/')
+      .expect(200)
+      .expect('Content-Type', /text\/html/);
+  });
+
+  it('exposes self-hosted explorer', async () => {
+    await client
+      .get('/explorer/')
+      .expect(200)
+      .expect('Content-Type', /text\/html/)
+      .expect(/<title>LoopBack API Explorer/);
+  });
+});