Axios Post whit laravel Error Request failed with status code 500

I am using Laravel with Vue making http request with the axios. It is returning a 500 error.

My request code is

registrarOperador() 
      {
        let me  = this;

        axios.post('/usuario/registrar',{
          'cedula':this.cedula,
          'nombre':this.nombre,
          'tele1':this.tele1,
          'tele2':this.tele2,
          'correo':this.correo,
          'direccion':this.direccion,
          'user_name':this.user_name,
          'user_pass':this.user_pass,
          'fecha_ingreso':this.fecha_ingreso,
          'estado':this.estado,
          'usu_idrol':this.usu_idrol


        }).then(function (response) {
          me.cerraModal();
          me.listarUsuario();
        }).catch(function (error) {
          console.log(error.message);
        });

Laravel Route

Route::post('/usuario/registrar', 'UsuariosController@store');

Controller

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use App\Categoria;

class CategoriaController extends Controller
{
/**
 * Display a listing of the resource.
 *
 * @return \Illuminate\Http\Response
 */
public function index()
{
    $categorias = Categoria::all();
    return $categorias;
}   

/**
 * Store a newly created resource in storage.
 *
 * @param  \Illuminate\Http\Request  $request
 * @return \Illuminate\Http\Response
 */
public function store(Request $request)
{
    $categoria = new Categoria();
    $categoria->nombre = $request->nombre;
    $categoria->descripcion = $request->descripcion;
    $categoria->condicion = '1';
    $categoria->save();
}

via Chebli Mohamed