update the user-agent in the latest version

Author: aaronm67

src/Vimeo/Vimeo.php

@@ -35,7 +35,7 @@ class Vimeo
     const CLIENT_CREDENTIALS_TOKEN_ENDPOINT = '/oauth/authorize/client';
     const VERSIONS_ENDPOINT = '/versions';
     const VERSION_STRING = 'application/vnd.vimeo.*+json; version=3.4';
-    const USER_AGENT = 'vimeo.php 3.0.8; (http://developer.vimeo.com/api/docs)';
+    const USER_AGENT = 'vimeo.php 4.0.1; (http://developer.vimeo.com/api/docs)';
     const MAX_BACKOFF = 8;
 
     /** @var array */