Added current_sign_in_at field to User modal

Handle dots and slashes when encoding. Fixes GitLabPHP#86 GitLabPHP#87

- Support authentication via OAuth

- Expose avatar_url in Project Model
- Refactor of project hook endpoints (breaking change)

Project sorting tests and saving group member test

Merge pull request GitLabPHP#47 from davidkuridza/bug/fix-wrong-MR-co…

…mments-endpoint

fix wrong comments endpoint for merge requests

Merge pull request GitLabPHP#45 from iamluc/master

Get file API

Added pagination support to Users::all(). Fixes GitLabPHP#24.

Merge pull request GitLabPHP#19 from ivankristianto/master

add project search function

Merge pull request GitLabPHP#16 from berni2288/master-fixpropertyerror

Fixes uncaught RuntimeException 'Property "xyz" does not exist

Added support for new fields added in 6.2 (iid etc) and added methods…

… to remove projects