test_py3kwarn had been overlooked when test.test_support.catch_warning() was
re-implemented to use warnings.catch_warnings() and had its API improved.

Closes issue #3768.
Code review by Benjamin Peterson.
diff --git a/Misc/NEWS b/Misc/NEWS
index f0da457..33866df 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -100,6 +100,11 @@
 - Issue #3643: Added a few more checks to _testcapi to prevent segfaults by
   exploitation of poor argument checking.
 
+Tests
+-----
+
+- Issue 3768: Move test_py3kwarn over to the new API for catch_warnings().
+
 
 What's New in Python 2.6 beta 3?
 ================================