Paint it Black by the Rolling Stones (#920)

diff --git a/tests/conftest.py b/tests/conftest.py
index 366624e..5bae6b8 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -12,7 +12,7 @@
 
     return "OpenSSL: {openssl}\ncryptography: {cryptography}".format(
         openssl=OpenSSL.SSL.SSLeay_version(OpenSSL.SSL.SSLEAY_VERSION),
-        cryptography=cryptography.__version__
+        cryptography=cryptography.__version__,
     )