Added comment to explain sorting rdfa in tests

Author: Cristi Constantin

tests/test_extruct.py

@@ -16,6 +16,8 @@ def test_all(self):
         body = get_testdata('songkick', 'elysianfields.html')
         expected = json.loads(get_testdata('songkick', 'elysianfields.json').decode('UTF-8'))
         data = extruct.extract(body, base_url='http://www.songkick.com/artists/236156-elysian-fields')
+        # Sorting the values here because RDFa is not preserving ordering on duplicated properties.
+        # See https://github.com/scrapinghub/extruct/issues/116
         for rdf in data['rdfa']:
             for key, pairs in rdf.items():
                 if ':' in key and isinstance(pairs, list):