[Fix] Facade: Added facade to package

src/Facades/Cart.php

@@ -0,0 +1,16 @@
+<?php
+namespace Gloudemans\Shoppingcart\Facades;
+
+use Illuminate\Support\Facades\Facade;
+
+class Cart extends Facade {
+    /**
+     * Get the registered name of the component.
+     *
+     * @return string
+     */
+    protected static function getFacadeAccessor()
+    {
+        return 'cart';
+    }
+}