Add created_at to output.
API for creating new users #13
Merge branch 'dev' of https://github.com/devscoutsweden/scoutapi into dev

Conflicts:
	config/routes.rb
	db/schema.rb
Requiring user to be set when creating objects, such as activities #13
API for categories #4
Reverting requirement that user must be set when creating activities #13
Activity revisions not returned in correct order for PostgreSQL #14
Activity revisions not returned in correct order for PostgreSQL #14