title: Aurelia Child Router redirect to specific route
body: <p>I have a main App router and multiple child routers.  I'd like to have the option of specifying the child route to open when navigating from the parent route.</p>
  
  <p><strong>Parent Router:</strong></p>
  
  <pre><code>configureRouter(config, router) {
    this.router = router;
    config.map([
      { route: ['','home'],      name: 'home',         moduleId: 'home/home' },
      { route: 'students/:id?',  name: 'students',     moduleId: 'students/students' },
      { route: 'staff',          name: 'staff',        moduleId: 'staff/staff' }
    ]);
  }
  </code></pre>
  
  <p><strong>Child Router for Students:</strong></p>
  
  <pre><code>export class Students {
  
    configureRouter(config, router) {
      config.map([
        { route: ['', 'home'],    name: 'student-home',           moduleId: 'students/students-home' },
        { route: 'list',          name: 'student-list',           moduleId: 'students/student-list' },
        { route: 'profile/:id',   name: 'student-profile',        moduleId: 'students/profile/overview' },
        { route: 'lockers',       name: 'student-lockers',        moduleId: 'students/lockers/home' }
      ]);
      this.router = router;
    }
  
    activate(params) {
      if (params.id) {
        console.log("Going straight to a student record for: ", params);
        this.router.navigateToRoute('student-profile', {id: params.id});
      }
    }
  }
  </code></pre>
  
  <p>The above scenario (using <code>navigateToRoute()</code> within activate) doesn't work, nor am I sure it's the best way.  How can I have the option to navigate straight from the main app router to the student-profile screen if I include an id param?</p>