Updated README & fixed tests

Author: toonvandenbos

README.md

@@ -17,8 +17,8 @@ This package's only purpose is to build custom repeated layout components, such
     - `buildUsing($callback)`
     - `insert($key, $attributes, $index, $id)`
 - serializing the flexible container's state
-    - `serialize($resource, $attribute)`
-    - `serializeAs($format, $resource, $attribute)`
+    - `serialize()`
+    - `serializeAs($format)`
     - `serializeUsingFormat($format)`
     - `serializeUsing($callback)`
 - get all inserted instances, and manipulate the LayoutCollection :

tests/Unit/InstanceResolvingTest.php

@@ -168,4 +168,4 @@
         });
 
     expect($flexible->serialize())->toBe('foo0,bar1,foo2');
-})->only();
+});