title: Matched route not changing on routing hash change
body: <p>I'm using <code>react-router-dom</code> with <code>react-router-redux</code> and <code>history</code> to manage routing for my app. I'm also using hash history for support on legacy browsers. Below are my route components:</p>
  
  <pre><code>&lt;Switch&gt;
      &lt;Route exact path={'/'} component={...} /&gt;
      &lt;Route path={'/a'} component={...} /&gt;
      &lt;Route path={'/b'} component={...} /&gt;
  &lt;/Switch&gt;
  </code></pre>
  
  <p>My app lands at the location: <code>http://something.com/index.html#/</code>, and correctly is routed to the first <code>Route</code> component. However, when using <code>dispatch(push('/a'))</code> in a thunk action creator to attempt to programatically switch routes, I'm finding that the proper route is not being matched.</p>
  
  <p>I'm having a difficult time debugging this... any ideas? I'm thinking it perhaps has to do with the fact that my <code>window.location.pathname</code> is <code>/index.html</code>.</p>