title: Angular 2 url construction with '@' symbol
body: <p>How do I add '@' symbol while constructing routes</p>
  
  <p>like <code>localhost/@user</code></p>
  
  <p>I tried </p>
  
  <pre><code>{
      path:'\@:username',
      component:ProfileComponent
  }
  </code></pre>
  
  <p>and</p>
  
  <pre><code>{
      path:"'\@':username",
      component:ProfileComponent
  }
  </code></pre>
  
  <p>no success</p>
  
  <p>I should Only get the Username as param,
  one possible solution is I can do this </p>
  
  <pre><code>{
      path:':username',
      component:ProfileComponent
  }
  </code></pre>
  
  <p>and remove '@' in the ": param ,use param,
  Is there any way I can get the first one working?</p>