The Repo Labels `update` method is incorrect

[bobeagan]

php-github-api/lib/Github/Api/Repository/Labels.php

Line 36 in 94dec1e

if (!isset($params['name'], $params['color'])) {

The actual parameter should be "new_name" and all parameters are optional to include.
https://developer.github.com/v3/issues/labels/#parameters-1

Additionally, the Repo Labels appears to be missing a related documentation page.

[acrobat]

@bobeagan Thanks for reporting this issue! Can you create a PR to fix the param and maybe a docs entry? Thanks!

[bobeagan]

@acrobat PR ready for your review

[bobeagan]

Hoping for a patch fix to be pushed to packagist after this gets merged so I can make use of it in my project without workarounds :)