Use WP_Http constants for status codes

Author: rmccue

inc/class-client.php

@@ -5,6 +5,7 @@
 use WP\OAuth2\Tokens\Access_Token;
 use WP\OAuth2\Tokens\Authorization_Code;
 use WP_Error;
+use WP_Http;
 use WP_Post;
 use WP_Query;
 use WP_User;