title: Binding interface issue: Argument 1 passed to __construct() must implement interface
body: <p>I have an issue when I try to bind <code>StripePaymentGateway</code> to <code>PaymentGatewayInteface</code></p>
  
  <pre class="lang-php prettyprint-override"><code>namespace App\Billing;
  
  interface PaymentGatewayInteface
  {
      public function charge($amount, $token);
  }
  </code></pre>
  
  <pre class="lang-php prettyprint-override"><code>namespace App\Billing;
  
  use Stripe\Charge;
  
  class StripePaymentGateway
  {
      private $apiKey;
  
      public function __construct($apiKey)
      {
          $this-&gt;apiKey = $apiKey;
      }
  
      public function charge($amount, $token)
      {
          // code
      }
  }
  </code></pre>
  
  <p>My AppServiceProvider:</p>
  
  <pre class="lang-php prettyprint-override"><code>namespace App\Providers;
  
  use App\Billing\StripePaymentGateway;
  use App\Billing\PaymentGatewayInteface;
  use Illuminate\Support\ServiceProvider;
  
  class AppServiceProvider extends ServiceProvider
  {
      public function register()
      {
          $this-&gt;app-&gt;bind(StripePaymentGateway::class, function () {
              return new StripePaymentGateway(config('services.stripe.secret'));
          });
  
          $this-&gt;app-&gt;bind(PaymentGatewayInteface::class, StripePaymentGateway::class);
      }
  }
  </code></pre>
  
  <pre class="lang-php prettyprint-override"><code>namespace App\Http\Controllers;
  
  use App\Billing\PaymentGatewayInteface;
  
  class ConcertsOrdersController extends Controller
  {
      private $paymentGateway;
  
      public function __construct(PaymentGatewayInteface $paymentGateway)
      {
          $this-&gt;paymentGateway = $paymentGateway;
      }
  }
  </code></pre>
  
  <p>This error is showing:</p>
  
  <pre><code>Symfony\Component\Debug\Exception\FatalThrowableError  : Argument 1 passed to App\Http\Controllers\ConcertsOrdersController::__construct() must implement interface App\Billing\PaymentGatewayInteface, instance of App\Billing\StripePaymentGateway given
  </code></pre>