//My isValid function inside Users.php model
    public function isValid($id = null)
    {
        //  If we are updating, ignore the unique username rule by adding user id to rules array.
        $rules = array(
            'email'     => 'required|max:100|unique:users,email,' . $id,
            'username'     => 'required|max:32|unique:users,' . $id
        );
        $validation = Validator::make($this->attributes, $rules, static::$validationMessages);

        if ($validation->passes()){
            return true;
        }
        $this->messages = $validation->messages();
        return false;
    }