Switch to new Framework :: Zope :: 3 classifier

See zopefoundation/z3c.authviewlet#6 (comment)
for the background behind this.

setup.py

@@ -50,7 +50,7 @@ def read(*rnames):
           'Natural Language :: English',
           'Operating System :: OS Independent',
           'Topic :: Internet :: WWW/HTTP',
-          'Framework :: Zope3'],
+          'Framework :: Zope :: 3'],
       url='http://pypi.python.org/pypi/zope.renderer',
       license='ZPL 2.1',
       packages=find_packages('src'),