context.events should use dot notation

[timwis]

Ideally we'd be able to do something like this:

          event_names = [event.action.name for event in events]
          if 'Approve Taxes' in event_names and 'Approve Parking' in event_names:
            change_state('Approved')

But currently we have to use:

          event_names = [event['action']['name'] for event in events]

Not a huge deal, just easier to write.
Related to #20