Fix bug where destroying a namespace would not always destroy projects
    
There is a race condition in DestroyGroupService now that projects are deleted asynchronously:
    
1. User attempts to delete group
2. DestroyGroupService iterates through all projects and schedules a Sidekiq job to delete each Project
3. DestroyGroupService destroys the Group, leaving all its projects without a namespace
4. Projects::DestroyService runs later but the can?(current_user,
    :remove_project) is `false` because the user no longer has permission to
    destroy projects with no namespace.
5. This leaves the project in pending_delete state with no namespace/group.
 
Projects without a namespace or group also adds another problem: it's not possible to destroy the container registry tags, since `container_registry_path_with_namespace` is the wrong value.

The fix is to destroy the group asynchronously and run `execute` directly on Projects::DestroyService.
 
Closes #17893

See merge request !4341

Update ruby 2.3.1

We where using 2.3.0, now 2.3.1

cc @connorshea 

See merge request !5790

Resolve "Format branch, tag, and commit in environment list"

## What does this MR do?
Updates Environments page rows to match the new pipeline updates

## Are there points in the code the reviewer needs to double check?
I removed `private` from `avatars_helper.rb` so I could use `user_avatar`.

## What are the relevant issue numbers?
Closes #20059 

## Screenshots (if relevant)
![Screen_Shot_2016-08-08_at_11.44.36_AM](/uploads/62fbb475a7d9cc613fe5ba1715229553/Screen_Shot_2016-08-08_at_11.44.36_AM.png)
![Screen_Shot_2016-08-08_at_11.44.41_AM](/uploads/ce1bd3ab62c0bc8091e9b6f85012ed36/Screen_Shot_2016-08-08_at_11.44.41_AM.png)



See merge request !5687

Instrument Project.visible_to_user

## What does this MR do?

This MR instruments `Project.visible_to_user`

## Are there points in the code the reviewer needs to double check?

No.

## Why was this MR needed?

The method in question was not instrumented due to being a Rails scope.

## What are the relevant issue numbers?

#12425

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- Tests
  - [ ] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [ ] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5793