Models

Estado

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Estado extends Model
{
    protected $fillable = ['sigla', 'descricao'];

	public static function listEstados()
	{
		return static::orderBy('sigla')->pluck('sigla', 'id');
	} 
}

User

<?php

namespace App;

use Illuminate\Notifications\Notifiable;
use Illuminate\Foundation\Auth\User as Authenticatable;

class User extends Authenticatable
{
    use Notifiable;

    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */

    protected $table = 'users';

    protected $fillable = [
        'name', 
        'email', 
        'password', 
        'cep', 
        'uf', 
        'endereco', 
        'telefone', 
        'tipousuario', 
        'estadoid', 
        'relacaoid'
    ];

    /**
     * The attributes that should be hidden for arrays.
     *
     * @var array
     */

     public static function listUser()
    {
        return static::orderBy('name')->pluck('name', 'id');
    }
    public function estado()
    {
        return $this->belongsTo('App\Estado', 'estadoid');
    }

    protected $hidden = [
        'password', 'remember_token',
    ];
}