Added support for ssl_get_version
diff --git a/src/cryptography/hazmat/bindings/openssl/ssl.py b/src/cryptography/hazmat/bindings/openssl/ssl.py
index 8359c05..b182180 100644
--- a/src/cryptography/hazmat/bindings/openssl/ssl.py
+++ b/src/cryptography/hazmat/bindings/openssl/ssl.py
@@ -306,6 +306,7 @@
 long SSL_CTX_get_timeout(const SSL_CTX *);
 
 const SSL_CIPHER *SSL_get_current_cipher(const SSL *);
+const char *SSL_get_version(const SSL *);
 int SSL_version(const SSL *);
 
 /* SNI APIs were introduced in OpenSSL 1.0.0.  To continue to support