title: Child route is not reached
body: <p>I have the following routing structure</p>
  
  <pre><code>{
          path: 'patients',
          children: [
            { path: '', component: PatientsComponent },
            {
              path: ':id', component: PatientComponent, children: [
                {
                  path: 'sessions',
                  children: [
                    { path: ':id', component: SessionComponent },
                    { path: '', component: SessionsComponent }
                  ]
                }
              ]
            }
          ]
        },
  </code></pre>
  
  <p>I can access <code>/patients</code> and <code>/patients/:id</code> but i cannot reach <code>/patients/:id/sessions</code> or <code>/patients/:id/sessions/:id</code></p>
  
  <p>Any reason why?</p>