1.04 upgrade

@Bjwebb - I think this all that needs to be done to make this application deal with 1.04. Please can you check. I've added a new test to check the basic validation stuff.

The application still has issues about choosing the schema version etc, but this brings it up to date and means it works in the same way as it does currently.

For https://github.com/IATI/IATI-Public-Validator/issues/52