title: No provider for Token AppId
body: <p>I have a unit test that is verifying the application's APP_ID is a fixed value.  The problem is, I don't know how to set the APP_ID so that it's not randomly generated.  </p>
  
  <p>The documentation from the Angular2 team's website is helpful enough, but I'm not sure if I'm interpreting it correctly:</p>
  
  <blockquote>
    <p>If you need to avoid randomly generated value to be used as an application id, you can provide a custom value via a DI provider configuring the root Injector using this token.</p>
  </blockquote>
  
  <p>So does this mean I'd add it as a provider in my app's bootstrap?</p>
  
  <pre><code>bootstrap(App, [
      provide(APP_ID, {name: 'MyApp'})
  ]);
  </code></pre>
  
  <p>I doubt that's remotely close.  Has anyone else figured out how to set the APP_ID or what it's even used for?</p>
  
  <p><strong>injector.spec.ts</strong></p>
  
  <pre><code>import {
  it,
  inject,
  injectAsync,
  beforeEachProviders,
  TestComponentBuilder
  } from 'angular2/testing';
  import {APP_ID} from 'angular2/core';
  
  
  describe('default test injector', () =&gt; {
    it('should provide default id', inject([APP_ID], (id) =&gt; {
      expect(id).toBe('MyApp');
    }));
  });
  </code></pre>