GitLab

Summary:
* Phabricator creates a mirror of Cygnus at GitLab
* GitLab can run different checks against Cygnus
* Configured php-lint for PHP 5.4, PHP 5.6 and PHP 7.0
* We make sure that all PHP versions are still working

Reviewers: O1 Luke081515Bot, Morten_Haan

Reviewed By: O1 Luke081515Bot, Morten_Haan

Subscribers: Morten_Haan, MGChecker

Tags: #cygnus

Differential Revision: https://rcm-2.wmflabs.org/D464