Update the tests to work with the code that was changed in rev 4dab932c94 to be more like the original c#

GildedRose/python/texttest_fixture.py

@@ -26,4 +26,4 @@ if __name__ == "__main__":
         for item in items:
             print(item)
         print("")
-        update_quality(items)
+        GildedRose(items).update_quality()