Validates the given changeset looking for the cep field, it allows customization of lookup field and error messages.

Example

struct
|> cast(params, @fields)
|> validate_cep

It will look up for a field named :cep to acquire the value, if you do not use this name on field you can customize as second arity.

Example

 struct
 |> cast(params, @fields)
 |> validate_cep(:street_cep)