Add tests for Flask views

tests/response_util.py

@@ -0,0 +1,13 @@
+# -*- encoding: utf-8 -*-
+from xml.etree import ElementTree
+
+
+def meal_names(response):
+    """Extract meal names from OpenMensa XML.
+
+    By no means below parsing is robust or complete. Below just helps ensuring that the parser indeed returns proper XML
+    instead of arbitrary responses."""
+    root = ElementTree.fromstring(response)
+    namespace = {'om': 'http://openmensa.org/open-mensa-v2'}
+    nodes = root.findall('om:canteen/om:day/om:category/om:meal/om:name', namespace)
+    return [node.text for node in nodes]