Fix `::properties` which modified the options hash while iterating properties.
Add failing test for ActiveRecord uniqueness validation with scope option
`::validates_uniqueness_of` now accepts options like `:scope`. fixes #125.
move ::validate test to validate_test :)
When overriding a reader method for a nested form for presentation (e.g. to provide an initial new record), this reader was used in `#update!`. The deserialize/update run now grabs the actual nested form instances directly from `fields`.
Fix failing test for ActiveRecord uniqueness validation with scope option

- Add missing created_at attribute