Start writing doc about GitLab architecture for developers

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
New gem versions

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Merge branch 'master' of github.com:gitlabhq/gitlabhq