[test] remove boilerplate in test_import _ddg4

DDTest/python/test_import_ddg4.py

@@ -5,8 +5,8 @@ This file adds a test for the DDG4 python module.
 """
 
 from __future__ import absolute_import
-import pytest
 from test_import import test_module
 
+
 def test_module_ddg4():
     test_module('DDG4')