Python 2 compatibility.

Author: rwgk

tests/test_make_caster_adl.py

@@ -10,7 +10,7 @@ def test_mock_caster():
 
 def test_minimal_real_caster():
     assert m.obj_mrc_return() == 1404
-    assert m.obj_mrc_arg("ignored") == 2303
+    assert m.obj_mrc_arg(u"ignored") == 2303
     with pytest.raises(TypeError) as excinfo:
         m.obj_mrc_arg(None)
     assert "(arg0: adl_mrc::type_mrc) -> int" in str(excinfo.value)