Revert "Use setuptools <34"

This reverts commit 632b6015.

Since version 36, setuptools bundles again instead of having dependencies.

buildout.cfg

@@ -4,7 +4,6 @@ parts = test oltest py
 versions = versions
 
 [versions]
-setuptools = 33.1.1
 zope.interface = 4.1.3
 zope.exceptions = 4.0.8
 zc.recipe.testrunner = 2.0.0