title: Return custom response with mitmproxy
body: <p>I'm trying to return custom response when using mitmproxy with the following code</p>
  
  <pre><code>from libmproxy.models import HTTPResponse
  from netlib.http import Headers
  
  def request(context, flow):
      if flow.request.pretty_url.endswith("example.com/index.php"):
          resp = HTTPResponse(
              [1, 1], 200, "OK",
              Headers(Content_Type="text/html"),
              "&lt;html&gt;&lt;body&gt;hello world&lt;/body&gt;&lt;/html&gt;")
          flow.reply(resp)
  </code></pre>
  
  <p>But the result is not as expected, in browser it shows up with http status codes, headers och body as clear text</p>
  
  <pre><code>[1,1] 200 OK
  Content-Type: text/html
  
  &lt;html&gt;&lt;body&gt;hello world&lt;/body&gt;&lt;/html&gt;
  </code></pre>
  
  <p>how can i return it as actual "http" response so that chrome render it as html?</p>