Merge pull request aws#676 from NSmithUK/master

Use late static binding for self instantiating the DynamoDb SessionHandler

src/DynamoDb/SessionHandler.php

@@ -66,7 +66,7 @@ public static function fromClient(DynamoDbClient $client, array $config = [])
             $connection = new StandardSessionConnection($client, $config);
         }
 
-        return new self($connection);
+        return new static($connection);
     }
 
     /**