Upgrade pyopenssl to run with new versions of OpenSSL

[abstractj]

Good morning, I'm running Python 2.7.10, OpenSSL 1.0.2a and setuptools 17.1. At the moment I get:

Downloading https://pypi.python.org/packages/source/p/pyOpenSSL/pyOpenSSL-0.13.tar.gz#md5=767bca18a71178ca353dff9e10941929
Processing pyOpenSSL-0.13.tar.gz
Writing /tmp/easy_install-S93TOt/pyOpenSSL-0.13/setup.cfg
Running pyOpenSSL-0.13/setup.py -q bdist_egg --dist-dir /tmp/easy_install-S93TOt/pyOpenSSL-0.13/egg-dist-tmp-G5ljIs
warning: no previously-included files matching '*.pyc' found anywhere in distribution
OpenSSL/crypto/crl.c:6:23: error: static declaration of ‘X509_REVOKED_dup’ follows non-static declaration
 static X509_REVOKED * X509_REVOKED_dup(X509_REVOKED *orig) {
                       ^
In file included from /usr/include/openssl/ssl.h:156:0,
                 from OpenSSL/crypto/x509.h:17,
                 from OpenSSL/crypto/crypto.h:30,
                 from OpenSSL/crypto/crl.c:3:
/usr/include/openssl/x509.h:751:15: note: previous declaration of ‘X509_REVOKED_dup’ was here
 X509_REVOKED *X509_REVOKED_dup(X509_REVOKED *rev);

This pull request pretty much fixes the issue, already reported here: #155

[HenryHoggard]

Closed: See #182