title: How to test custom handler500?
body: <p>I write my handler for server errors and define it at root urls.py:
  handler500 = 'myhandler'
  And I want to write unittest for testing how it works. For testing I write view with error and define it in test URLs configuration, when I make request to this view in browser I see my handler and receive status code 500, but when I launch test that make request to this view I see stack trace and my test failed. Have you some ideas for testing handler500 by unittests?</p>