title: Aurelia-router router.navigation does not refresh when a route property is updated
body: <p>The <code>nav</code> property of my <code>create-team</code> route is set by an observable property in my <code>userService</code>. 
  I have one problem though. There is no way to refresh the <code>router.navigation</code> array to reflect that my property <code>isTeamMember</code> has changed. So even if my <code>isTeamMember</code> property returns true then the route would not be hidden unless I do a full page refresh.</p>
  
  <p>I tried with <code>router.refreshNavigation()</code> and it did not work, since from what I understand only routes that are set to <code>nav: true</code> will be added to the <code>router.navigation</code> array.</p>
  
  <p>I'm currently looping through <code>router.navigation</code> array to display my menu for my app. But when the user create a team I would like to hide that route from the menu since the user is now a team owner. I handle access to that route with an <code>AuthorizeStep</code> which works but would also like to hide this route dynamically.</p>
  
  <p>app.ts</p>
  
  <pre><code>configureRouter(config: RouterConfiguration, router: Router){
  ...
      var appRoutes = [
          { route: '/create-team', name:'create-team', moduleId: 'routes/create-team', nav: !this.userService.isTeamMember, title: 'menu.create-team', settings: { auth: { isNotTeamMember: true } } },
      ]
  ...
  }
  </code></pre>
  
  <p>Is there a clean way to refresh the <code>route.navigation</code> array so my menu is updated without having to do a full page refresh?</p>