River notifications on create may be trigged before post is actaully created in db

[skogsmaskin]

River-notifications are sent :after_create, however the writing in the database is done as a transaction. In some circumstances this result in a notification which might be put out on the river and read by consumers before the post is actually readable by the API.

We may consider not to use the ActiveRecord observer, but manually trigger the notification at the end of the transaction that produce new posts.