follow up to bug 1007 commit.

Use self.assertTrue in test cases rather than the assert statement.

Lib/test/test_dumbdbm.py

@@ -92,7 +92,7 @@ class DumbDBMTestCase(unittest.TestCase):
     def test_write_contains(self):
         f = dumbdbm.open(_fname)
         f[b'1'] = b'hello'
-        assert b'1' in f
+        self.assertTrue(b'1' in f)
         f.close()
 
     def test_write_write_read(self):

Lib/test/test_whichdb.py

@@ -35,9 +35,9 @@ class WhichDBTestCase(unittest.TestCase):
             f = module.open(_fname, 'w')
             f[b"1"] = b"1"
             # and test that we can find it
-            assert b"1" in f
+            self.assertTrue(b"1" in f)
             # and read it
-            assert f[b"1"] == b"1"
+            self.assertTrue(f[b"1"] == b"1")
             f.close()
             self.assertEqual(name, whichdb.whichdb(_fname))