Add status code `429 Too Many Requests`

src/Network/Response.php

@@ -69,6 +69,7 @@ class Response
         415 => 'Unsupported Media Type',
         416 => 'Requested range not satisfiable',
         417 => 'Expectation Failed',
+        429 => 'Too Many Requests',
         500 => 'Internal Server Error',
         501 => 'Not Implemented',
         502 => 'Bad Gateway',