Update method improved in db api

Model is fetched from db in a separate session after update.
It is important to reload an entry, so that is has a correct updated_at
column.

Change-Id: Ia19139dd66ff0e3d412d13505d568545694e4ea7

storyboard/db/api/base.py

@@ -225,9 +225,14 @@ def entity_update(kls, entity_id, values):
         if entity is None:
             raise exc.NotFound("%s %s not found" % (kls.__name__, entity_id))
 
-        entity.update(values.copy())
+        values_copy = values.copy()
+        values_copy["id"] = entity_id
+        entity.update(values_copy)
         session.add(entity)
 
+    session = get_session()
+    entity = __entity_get(kls, entity_id, session)
+
     return entity