Mapping for validation errors

[mpkhr]

Hi guys,

small idea to improve the gem: It would be great to have a mapping for validation errors, as to the user those fields remain a boolean.

Use case is: there is some business logic behind a field. If the user runs in such validation errors, the validation errors shouldn't be added to :completed_at, but rather to :completed, which is what is then used in the forms.

Can all be done manually of course, but I think this would be a nice addition to connect the pieces between forms, validations and the "behind the scenes" timestamp field.

Thanks!