Laravel 5 Payum provider not working

Question

I have installed payum for laravel 5 but my providers are not updating correctly.

I added 'Payum\LaravelPackage\PayumServiceProvider' to app/config/app.php file.

'providers' => [
     ...      
     //All my providers
    'Payum\LaravelPackage\PayumServiceProvider',
],

also tried as

'providers' => [
     ...      
     //All my providers
     Payum\LaravelPackage\PayumServiceProvider::class,
],

anyway the error message i get whenever i try to use artisan to make a controller or any other thing is:

am i missing any configuration for the service provider? any help will be apreciated.

EDIT: i have created a new provider and stopped using the default provider.

i ran php artisan make:provider PayumServiceProvider

and into its register method pasted:

...
public function register()
{
    $this->app->resolving('payum.builder', function(\Payum\Core\PayumBuilder $payumBuilder) {
        $payumBuilder
        // this method registers filesystem storages, consider to change them to something more
        // sophisticated, like eloquent storage
        ->addDefaultStorages()

        ->addGateway('paypal_ec', [
            'factory' => 'paypal_express_checkout',
            'username' => 'EDIT ME',
            'password' => 'EDIT ME',
            'signature' => 'EDIT ME',
            'sandbox' => true
        ]);
    });
}
...

Still not working