4.3 and require ZODB 4 (not 5)

CHANGES.rst

 Changelog
 =========
 
-4.2.2 (unreleased)
+4.3.0 (2016-08-02)
 ------------------
 
+- Refuse to work with ZODB 5.
+
+  Some recent cleanups in the ZODB commit protocol are incompatible with ZEO 4.
+
 - Fix ZEO cache tracing on Python 3.
 
 4.2.1 (2016-06-30)

setup.py

@@ -12,7 +12,7 @@
 #
 ##############################################################################
 
-version = '4.2.1'
+version = '4.3.0'
 
 from setuptools import setup, find_packages
 import os
@@ -119,7 +119,7 @@ setup(name="ZEO",
       tests_require = tests_require,
       extras_require = dict(test=tests_require),
       install_requires = [
-          'ZODB >= 4.2.0b1',
+          'ZODB >= 4.2.0b1, <4.999',
           'six',
           'transaction',
           'persistent >= 4.1.0',