Controllers are now expecting for the Illuminate\Database\Capsule\Manager instance instead of Vesp\Services\Eloquent
You can manually configure this service or just register the Vesp service in the container:
<?php
require dirname(__DIR__) . '/core/bootstrap.php';
$container = new DI\Container();
$container->set(Illuminate\Database\Capsule\Manager::class, new Vesp\Services\Eloquent());
$app = DI\Bridge\Slim\Bridge::create($container);
// ...This change makes using of vesp/core in other systems more convenient.