title: Flask test_client removes query string parameters
body: <p>I am using Flask to create a couple of very simple services. From outside testing (using HTTPie) parameters through querystring are getting to the service. </p>
  
  <p>But if I am using something like.</p>
  
  <pre><code>    data = {
          'param1': 'somevalue1',
          'param2': 'somevalue2'}
  
      response = self.client.get(url_for("api.my-service", **data))
  </code></pre>
  
  <p>I can see the correct URI being created:</p>
  
  <pre><code>http://localhost:5000/api1.0/my-service?param1=somevalue1&amp;param2=somevalue2
  </code></pre>
  
  <p>when I breakpoint into the service:</p>
  
  <pre><code>request.args
  </code></pre>
  
  <p>is actually empty.</p>
  
  <p><code>self.client</code> is created by calling <code>app.test_client()</code> on my configured Flask application.</p>
  
  <p>Anyone has any idea why anything after <code>?</code> is being thrown away or how to work around it while still using <code>test_client</code>?</p>