add simple integration test

test/util.py

@@ -0,0 +1,13 @@
+# -*- coding: utf-8 -*-
+
+from collections.abc import Mapping
+
+
+class ConfigMock:
+    def __init__(self, configuration):
+        assert isinstance(configuration, Mapping)
+        assert all(isinstance(x, Mapping) for x in configuration.values())
+        self.configuration = configuration
+
+    def get(self, a, b):
+        return self.configuration[a][b]