Update AbstractExtensibleModel.php

Author: atwixfirster

lib/internal/Magento/Framework/Model/AbstractExtensibleModel.php

@@ -16,6 +16,7 @@
  * Implementations may choose to process custom attributes as their persistence requires them to.
  * @SuppressWarnings(PHPMD.NumberOfChildren)
  * @api
+ * @codeCoverageIgnore
  */
 abstract class AbstractExtensibleModel extends AbstractModel implements
     \Magento\Framework\Api\CustomAttributesDataInterface