Support universal wheels

setup.cfg

+[bdist_wheel]
+universal = 1
+
 [check-manifest]
 ignore =
     *.cfg
@@ -5,4 +8,4 @@ ignore =
     Makefile
     zc.recipe.egg_/*
     zc.recipe.egg_
-    tox.ini
+    tox.ini
\ No newline at end of file