`tempstorage` should only be a test requirement as it depends on `ZODB3 [test]` itself

buildout.cfg

@@ -31,7 +31,7 @@ initialization =
     import sys
     import warnings
     if sys.version_info >= (2, 7): warnings.simplefilter('default')
-eggs = Zope2
+eggs = Zope2 [test]
 
 
 [scripts]

setup.py

@@ -65,7 +65,6 @@ setup(name='Zope2',
       'initgroups',
       'pytz',
       'setuptools',
-      'tempstorage',
       'transaction',
       'zdaemon',
       'zExceptions',
@@ -106,7 +105,9 @@ setup(name='Zope2',
       'zope.traversing',
       'zope.viewlet',
     ] + additional_install_requires,
-
+    extras_require={
+      'test': ['tempstorage'],
+    },
     include_package_data=True,
     zip_safe=False,
     entry_points={