title: Accessing Lumen/Laravel URL params
body: <p>I guess I'm missing something really obvious here but how do you access URL params in Lumen? I have the following route:</p>
  
  <pre><code>$app-&gt;get('user/{id}', ['uses' =&gt; 'userController@testId']);
  </code></pre>
  
  <p>Then in my user controller I have:</p>
  
  <pre><code>public function testId(Request $request) {
  
      return $request-&gt;input('id');
  }
  </code></pre>
  
  <p>But the ID is always null what have I missed even in this very basic example?</p>