complete const test

python/paddle/v2/fluid/tests/test_const_value.py

@@ -5,6 +5,9 @@ import paddle.v2.fluid.framework as framework
 class ConditionalBlock(unittest.TestCase):
     def test_const_value(self):
         self.assertEqual(framework.GRAD_VAR_SUFFIX, "@GRAD")
+        self.assertEqual(framework.TEMP_VAR_NAME, "@TEMP@")
+        self.assertEqual(framework.GRAD_VAR_SUFFIX, "@GRAD")
+        self.assertEqual(framework.ZERO_VAR_SUFFIX, "@ZERO")
 
 
 if __name__ == '__main__':