Fix version check.

dulwich/tests/__init__.py

@@ -29,7 +29,7 @@ import tempfile
 
 # If Python itself provides an exception, use that
 import unittest
-if sys.version < (2, 7):
+if sys.version_info < (2, 7):
     from unittest2 import SkipTest, TestCase as _TestCase
 else:
     from unittest import SkipTest, TestCase as _TestCase