Require "new" version of setuptools and pbr.

See
http://docs.openstack.org/developer/pbr/compatibility.html#evaluate-marker

setup.py

@@ -1,11 +1,14 @@
 #!/usr/bin/env python
+# -*- coding: utf-8 -*-
 # Copyright (C) 2004-2005 Tristan Seligmann and Jonathan Jacobs
 # Copyright (C) 2012-2014 Bastian Kleineidam
-# Copyright (C) 2015 Tobias Gruetzmacher
+# Copyright (C) 2015-2016 Tobias Gruetzmacher
+
+from __future__ import absolute_import, division, print_function
 
 from setuptools import setup
 
 setup(
-    setup_requires=['pbr'],
+    setup_requires=['pbr>=1.9', 'setuptools>=17.1'],
     pbr=True,
 )