Fix CI permissions

![Screen_Shot_2015-09-21_at_20.23.16](https://gitlab.com/gitlab-org/gitlab-ce/uploads/6f40699507d0dce148d0054a093f0d63/Screen_Shot_2015-09-21_at_20.23.16.png)

This fixes two problems:
- Allow developers to retry builds
- Hide advanced project options from CI page for non-admin users

See merge request !1379