title: How do you programmatically update query params in react-router?
body: <p>I can't seem to find how to update query params with react-router without using <code>&lt;Link/&gt;</code>. <code>hashHistory.push(url)</code> doesn't seem to register query params, and it doesn't seem like you can pass a query object or anything as a second argument.</p>
  
  <p>How do you change the url from <code>/shop/Clothes/dresses</code> to <code>/shop/Clothes/dresses?color=blue</code> in react-router without using <code>&lt;Link&gt;</code>? </p>
  
  <p>And is an <code>onChange</code> function really the only way to listen for query changes? Why aren't query changes automatically detected and reacted-to the way that param changes are?</p>