title: Observable subscription not getting called
body: <p>I have an Observable that I'm using to convert a promise into a subscription. This results in a collection that I need to iterate through to call an HTTP Service on each element. I'm using forkJoin to wait for all those calls to finish so that I can do something else, but unfortunately, my subscription is not being called. Do you see what I'm missing here?</p>
  
  <pre><code>Observable.fromPromise(this.users.getElements()).subscribe(results =&gt; {
    Observable.forkJoin(
      results.map(
        aUser =&gt; this.HttpService.submitUser(aUser).subscribe(
          results =&gt; {
            this.progress += 1;
          },
          err =&gt; {
            this.progress += 1;
            this.handleError(&lt;any&gt;err);
          })
      ).subscribe(
        //it never gets to either of these calls after all service calls complete
        data =&gt; {
          debugger;
          console.log(data);
          this.reset();
        },
        err =&gt; {
          debugger;
          console.log(err);
          this.reset();
        }
      ));
  });
  </code></pre>