Add new pre-receive and post-receive hooks

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
GitlabAccess and GitlabPostReceive classes added

Gitlab Access handles security check. GitlabPostReceive creates a sidekiq job

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Add tests for GitlabPostReceive

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Remove update hook logic

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Version 2.0.0.pre. Requires GitLab 7.3+

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Update GitlabNet to match new logic

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Merge branch 'hooks-refactoring' into 'master'

Hooks refactoring

* replace update hook with pre-receive & post-receive hooks
* use pre-receive hook for authorisation
* use post-receive hook to create background job for GitLab worker

Related to https://dev.gitlab.org/gitlab/gitlabhq/issues/1516

See merge request !38