how extends form validation with custom file check validation?

Hi, i am trying to create a custom validation to verify the file type and desire, extend the form validation class, but I don't get results ...

my code:

https://gist.github.com/aguileraq/573e34...db348f30ed

and this is my response:

Code:

{
   "response":{
      "rank":"Campo obligatorio.",
      "name":"Campo obligatorio.",
      "first_lastname":"Campo obligatorio.",
      "second_lastname":"Campo obligatorio.",
      "birthday_day":"Campo obligatorio.",
      "birthday_month":"Campo obligatorio.",
      "birthday_year":"Campo obligatorio.",
      "registration_number":"Campo obligatorio.",
      "rfc":"Campo obligatorio.",
      "discharge_date":"Campo obligatorio.",
      "discharge_place":"Campo obligatorio.",
      "street":"Campo obligatorio.",
      "number":"Campo obligatorio.",
      "between_streets":"Campo obligatorio.",
      "suburb":"Campo obligatorio.",
      "city":"Campo obligatorio.",
      "zipcode":"Campo obligatorio.",
      "municipality":"Campo obligatorio.",
      "phone":"Campo obligatorio."
   },
   "res":"error"
}

All validation return a message but field picture return nothing...

any suggestion? thanks for your help