Adding a notification when no migrations need to be applied

[danielcompton]

Sometimes it is just as important to know when no migrations need to be applied as when migrations are applied. Currently Ragtime silently does nothing which is fine in some situations, but not always. One possible route for this would be to add a new op for logging-reporter to handle. Perhaps a :no-op to go with :up and :down?

What are your thoughts?

[weavejester]

Maybe instead of a :no-op, we have :begin and :end. The :begin event could be given the list of migrations, so you could work out whether a migration was being applied by checking the count.