Fixes #2154.
- Adding a validation
.valid
which does not actually validate something except the automatically thrown decoding errors. - Adding
.valid
as default validation if no validation is provided.
// OLD (+ workaround for bool)
validations.add("foo", as: Bool.self, is: .in([true, false]))
// NEW
validations.add("foo", as: Bool.self, is: .valid)
validations.add("foo", as: Bool.self) // is: can be omitted
validations.add("foo", as: Date.self) // works for all kind of properties