Replacing github example with httpbin

This is a follow up of a question by lokapujya from the IRC channel who was wondering why the example from the quickstart docs didn't work for him.

https://github.com/timeline.json has been removed and delivers a JSON message with a 410 HTTP Status code. The change to http://httpbin.org/get follows the other request examples.

Cheers!
:octocat: Jérôme