Trivial spelling: s/you/your/.
Add support for GitLab notifications.

This commit adds support for GitLab notifications (push webhooks) available at
the url endpoint: '/hooks/gitlab/'.

Summary of the changes:
* Add the url endpoint and the appropriate gitlab handler method.
* Add to 'Notification hooks' on data/<project>.
* Add tests.
* Update documentation.

This commit has been tested with GitLab CE 7.1.0.
Check for the content-type instead of the service name.
Merge pull request #500 from nblock/feature/gitlab-support

Feature/gitlab-support
Changelog entry (issue #500)

Signed-off-by: Michal Čihař <michal@cihar.com>
Register hook backends using decorator

This allows to simplify the code without explicitly listing all hook
backends in the handler.

Also remove not used csrf decorator on the hooks as they are never
called directly from the view.

See also issue #500.

Signed-off-by: Michal Čihař <michal@cihar.com>
Merge branch 'master' into bootstrap