fix class name used in the statements serializer

Author: xabbuh

Serializer/StatementSerializer.php

@@ -66,7 +66,7 @@ public function deserializeStatements($data)
     {
         return $this->serializer->deserialize(
             $data,
-            'array<Xabbuh\XApi\Storage\MongoDB\Document\Statement>',
+            'array<Xabbuh\XApi\Common\Model\Statement>',
             'json'
         );
     }