Update README.md

Author: voidgraphics

README.md

@@ -17,7 +17,7 @@ You must specify two things before beginning to use the API:
 $client = new Whitecube\MultiSafepay\Client('production', 'your-api-key');
 
 // Example: Get an existing order
-$order = $client->orders()->show('order-id');
+$order = $client->orders()->fetch('order-id');
 ```
 
 ### Orders
@@ -82,4 +82,4 @@ $client->orders()->update('order-id', [
     'status' => 'completed', 
     //...
 ]);
-```
+```