Upgrade knplabs/github-api

[reedy]

composer.json currently has knplabs/github-api at ^1.4, meaning 1.7.1 is installed. That seems to be from July 2016 - https://github.com/KnpLabs/php-github-api/tree/1.7.1

Installing that results in...

Package guzzle/guzzle is abandoned, you should avoid using it. Use guzzlehttp/guzzle instead.

Looking at this, it seems knplabs/github-api should actually be a require not a require-dev dependancy... Used in php/apsearch.php.

So it needs moving, and then upgrading...

[reedy]

Done this in #1109 because GitHub is crap at dependant packages, so it's all gotta go in there because of the needed dependancies in composer.json changes...