upgrade dependencies

this bug started surfacing, which has been reportedly fixed in a more recent version of guzzle

> PHP Warning:  count(): Parameter must be an array or an object that implements Countable in phar:///usr/local/bin/gpgl/vendor/guzzlehttp/guzzle/src/Handler/CurlFactory.php on line 67

https://github.com/guzzle/guzzle/issues/1973