Fix dependency to be on development version of cryptography

setup.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python
 # -*- coding: utf-8 -*-
 #
 # Copyright (C) Jean-Paul Calderone 2008-2014, All rights reserved
@@ -34,7 +34,7 @@
       maintainer_email = '[email protected]',
       url = 'https://github.com/pyca/pyopenssl',
       license = 'APL2',
-      install_requires=["cryptography>=0.5", "six>=1.5.2"],
+      install_requires=["cryptography>=0.5.dev1", "six>=1.5.2"],
       long_description = """\
 High-level wrapper around a subset of the OpenSSL library, includes
  * SSL.Connection objects, wrapping the methods of Python's portable