title: Laravel Numbers Only Validation
body: <p>How to validate only numbers in laravel?
  I've try numeric and digits but it accept + and - character as a valid numbers / digits which I don't want. (+123 or -123 is validated as valid numeric)</p>
  
  <p>Is there a existing rule on laravel that only accept 0-9 as a valid numbers or I have to go with regex instead?</p>