[BUG] Use correct semantics for default model values.
[FEATURE] Add validations to ripple_address model.
[FEATURE] add type to RippleAddress.create, send 500 if errors.
[FEATURE] Enable getting payments without arguments.
[FEATURE] No longer require user_id in ripple_addresses table.
[TEST] Creating independent ripple addresses without a user.
[CHORE] Bump patch.