Switch to new Framework :: Zope :: 3 classifier

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

setup.py

@@ -64,7 +64,7 @@ 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/z3c.menu.ready2go',
     packages = find_packages('src'),
     include_package_data = True,