fix test_py3kwarns
The fact that this was failing and went unnoticed so long seems like a good argument for being able to enable and disble py3kwarnings through Python.
diff --git a/Lib/plat-mac/buildtools.py b/Lib/plat-mac/buildtools.py
index 0081e65..3480226 100644
--- a/Lib/plat-mac/buildtools.py
+++ b/Lib/plat-mac/buildtools.py
@@ -1,8 +1,8 @@
"""tools for BuildApplet and BuildApplication"""
import warnings
-warnings.warn("the buildtools module is deprecated and is removed in 3.0",
- DeprecationWarning, 2)
+warnings.warnpy3k("the buildtools module is deprecated and is removed in 3.0",
+ stacklevel=2)
import sys
import os