ashwinks/PHP-LinkedIn-SDK — pull request #10 by povilas (2014-06-11 11:38:11+00:00)
Title: removed array typehinting for $payloayd

you must be able to send not only arrays, but also simple strings as JSON
$linkedin->put("/posts/xxx/category/code", "job");

last example in https://developer.linkedin.com/documents/api-requests-json