Workaround failing pypy gate job

Until a proper fix is found, pin the version of setuptools to one
that doesn't cause this issue.

Change-Id: I4f5f2b6449a90df06b366f9eb3f2c16bb37cc758
Related-Bug: #1290562

tox.ini

@@ -23,6 +23,10 @@ commands = {posargs}
 [testenv:cover]
 commands = python setup.py testr --coverage --testr-args='{posargs}'
 
+[testenv:pypy]
+deps = setuptools<3.2
+    -r{toxinidir}/requirements.txt
+    -r{toxinidir}/test-requirements.txt
 
 [tox:jenkins]
 downloadcache = ~/cache/pip