title: props.params in Enzyme test
body: <p>Im trying to test my component that makes a getJSON request in the componentWillMount lifecycle method. It has the following code:</p>
  
  <pre><code>api.getJSON(`users/${this.props.params.id}`)
              .done((result) =&gt; {
                  this.setState({user: result});
              });
  </code></pre>
  
  <p>As you can see it uses the props.params.id to make the request. The issue im having is in my test. When I run <code>npm test</code> it returns cannot read property of undefined, undefined being the <code>props.params</code>. How can I get this object in enzyme? </p>