Switch from Twisted's TestCase to the stdlib TestCase so there are fewer ways the test suite can be invoked
diff --git a/test/test_crypto.py b/test/test_crypto.py
index d83218b..28a2eba 100644
--- a/test/test_crypto.py
+++ b/test/test_crypto.py
@@ -4,7 +4,8 @@
Unit tests for L{OpenSSL.crypto}.
"""
-from unittest import TestCase, main
+from unittest import main
+
from os import popen2
from OpenSSL.crypto import TYPE_RSA, TYPE_DSA, Error, PKey, PKeyType
@@ -18,6 +19,7 @@
from OpenSSL.crypto import PKCS7Type, load_pkcs7_data
from OpenSSL.crypto import PKCS12Type, load_pkcs12
from OpenSSL.crypto import NetscapeSPKI, NetscapeSPKIType
+from OpenSSL.test.util import TestCase
cleartextCertificatePEM = """-----BEGIN CERTIFICATE-----