SluggableInterface laravel 5 model articulos

articulo.php

<?php namespace blog;

use Illuminate\Database\Eloquent\Model;

//EloquentSluggable library
use Cviebrock\EloquentSluggable\SluggableInterface;
use Cviebrock\EloquentSluggable\SluggableTrait;

class Articulo extends Model implements SluggableInterface{

	 use SluggableTrait;

	 protected $table = 'articulos';

	 protected $filliable = ["titulo", "contenido", "slug", "imagen", tags]

    protected $sluggable = array(
        'build_from' => 'titulo',
        'save_to'    => 'slug',
    );

}