Update Digest.php

changed basic auth to null (no auth) on the initial server call for digest.

src/Http/Client/Auth/Digest.php

@@ -83,7 +83,7 @@ protected function _getServerInfo(Request $request, $credentials)
         $response = $this->_client->get(
             $request->getUri(),
             [],
-            ['auth' => ['type' => 'basic']]
+            ['auth' => ['type' => null]]
         );
 
         if (!$response->getHeader('WWW-Authenticate')) {