Fatal error: Uncaught Error: Interface "GuzzleHttp\Promise\PromisorInterface" not found in /home/justin/projects/calsyncv2/calsync/vendor/guzzlehttp/guzzle/src/Pool.php:24 Stack trace: #0 {main} thrown in /home/justin/projects/calsyncv2/calsync/vendor/guzzlehttp/guzzle/src/Pool.php on line 24