Change the PyUnit-based tests to use the test_main() approach.  This
allows using the tests with unittest.py as a script.  The tests will
still run when run as a script themselves.
diff --git a/Lib/test/test_sha.py b/Lib/test/test_sha.py
index bc76809..cad7780 100644
--- a/Lib/test/test_sha.py
+++ b/Lib/test/test_sha.py
@@ -27,4 +27,9 @@
                    "34aa973cd4c4daa4f61eeb2bdbad27316534016f")
 
 
-test_support.run_unittest(SHATestCase)
+def test_main():
+    test_support.run_unittest(SHATestCase)
+
+
+if __name__ == "__main__":
+    test_main()