Apply fixes from StyleCI

Author: Codexshaper

src/Models/ShippingZoneMethod.php

@@ -8,7 +8,7 @@
 class ShippingZoneMethod extends BaseModel
 {
     use QueryBuilderTrait;
-    
+
     protected $endpoint = 'shipping_methods';
 
     /**

src/Models/System.php

@@ -8,7 +8,7 @@
 class System extends BaseModel
 {
     use QueryBuilderTrait;
-    
+
     protected $endpoint;
 
     /**

src/Models/Variation.php

@@ -8,7 +8,7 @@
 class Variation extends BaseModel
 {
     use QueryBuilderTrait;
-    
+
     protected $endpoint;
 
     /**