feat: add endpoint to return information for a specified cart

Author: ahinkle

src/Api/GuestCarts.php

@@ -14,10 +14,20 @@ public function create()
         return $this->post('/guest-carts');
     }
 
+    /**
+     * Enable a guest user to return information for a specified cart.
+     *
+     * @return array
+     */
+    public function cart($cartId)
+    {
+        return $this->get('/guest-carts/'.$cartId);
+    }
+
     /**
      * List items that are assigned to a specified cart.
      *
-     * @return string
+     * @return array
      */
     public function items($cartId)
     {

tests/Api/GuestCartsTest.php

@@ -26,6 +26,17 @@ public function test_can_call_guest_carts_create()
         $this->assertTrue($api->ok());
     }
 
+    public function test_can_call_guest_carts_cart()
+    {
+        Http::fake();
+
+        $magento = new Magento();
+
+        $api = $magento->api('guestCarts')->cart('foo');
+
+        $this->assertTrue($api->ok());
+    }
+
     public function test_can_call_guest_carts_items()
     {
         Http::fake();