title: Page props do not update when url query is updated
body: <p>I am using Gatsby 1.4.0</p>
  
  <p>I would like to have multiple buttons on a website that link to the same page, but with a different search query. For example, 2 buttons in a dummy page.:</p>
  
  <pre><code>Link A -&gt; Routes to '/test/?name=john
  Link B -&gt; Routes to '/test/?name=peter
  </code></pre>
  
  <p>I would like to use  from 'gatsby-link' to route a user to a new path so the page does not refresh.</p>
  
  <p><strong>Problem</strong></p>
  
  <p>Upon navigation, my layout file is re-rendered as expected, but my page file is not re-rendered. Only if I reload the page does the correct query get passed down to my page file.  </p>
  
  <p><strong>layout/index.js file (simplified):</strong></p>
  
  <pre><code>render() {
      console.log(this.props.location.search) // Correct query every time navigation occurs
      return (
        &lt;div&gt;
          {this.props.children()}
          &lt;Footer /&gt;
        &lt;/div&gt;
      )
    },
  </code></pre>
  
  <p><strong>pages/test.js</strong></p>
  
  <pre><code>import React from 'react'
  import Link from 'gatsby-link'
  
  export default class Dummy extends React.Component {
  
    render() {
      console.log(this.props.location.search) // Does not re-render on navigation.
  
      return (
        &lt;div&gt;
          &lt;Link to="/test/?name=john"&gt;John&lt;/Link&gt;
          &lt;Link to="/test/?name=peter"&gt;Peter&lt;/Link&gt;
        &lt;/div&gt;
      )
    }
  }
  </code></pre>
  
  <hr>
  
  <p>Is there a way to force the page to re-render when the query is updated? </p>