#39 fikset error i test

test/test_serialize_export_import.py

@@ -102,7 +102,7 @@ class SerializeTest(unittest.TestCase):
             "invalid_key": "All keys do not exist",
         }
         file = open(invalid_soi_file_path, "w")
-        file.write(str(invalid_serialization))
+        file.write(json.dumps(invalid_serialization))
         file.close()
         # Assert invalid serialization throws error on import
         with self.assertRaises(ValueError) as error: