* upstream/master: (237 commits)
  Grapify boards API
  Add test, fix merge error
  Use local assigns to get the dropdown title
  Updated issuable dropdown titles
  Added safety check for formatted values
  Minor style improvement
  Fixed conflict and corrected teaspoon test
  Rename method in test
  Moved ci_status environments logic to new action ci_envrionments_status and set up frontend polling
  Refactor ci_status on MergeRequestController
  Fix indenting error in HAML
  Show what time ago a MR was deployed
  Fixed missing links
  Fixed missing links
  Refactor merge requests revisions
  Add link to update docs for source installations
  Grapify todos API
  Link to review apps example from docs
  fix grafana_configuration.md move link
  Do not run before_script, artifacts, cache in trigger_docs job
  ...

Grapify boards API

## What does this MR do?

Add the Grape-DSL to the boards API.

## What are the relevant issue numbers?

Related to #22928

See merge request !6876

Updated issuable dropdown titles

## What does this MR do?

The dropdowns in the issuable form still had the filter dropdown titles, this fixes that by giving them their own titles.

Closes #23337

See merge request !6882

Feedback:
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6019#note_16956802

Fix grafana_configuration.md move link

See merge request !6871

Show deployed time ago

Closes #21652

cc @ayufan 

See merge request !6676

Reassign secret token when regenerating one

## What does this MR do?

This is an attempt to fix intermittent errors in out test suite.

```text
Failures:

  1) Gitlab::Shell memoized secret_token creates and links the secret token file
     Failure/Error: expect(File.read(secret_file).chomp).to eq(secret_token)
     
       expected: "690f959e206ab91acc54e1c605c7ff90"
            got: "cccb4e8df9360600271e61114d4e6e68"
     
       (compared using ==)
     # ./spec/lib/gitlab/backend/shell_spec.rb:47:in `block (3 levels) in <top (required)>'
```

It appears that `spec/lib/gitlab/backend/shell_spec.rb` tries to change the file that stores secret token, but `Gitlab::Shell` memoizes `@secret_token` on class level, so when it was already created by other tests (`spec/requests/api/internal_spec.rb` in this case), memoized token is not reassigned even if it was generated again with `ensure_secret_token!`.

See merge request !6844

Grapify todos API

## What does this MR do?

Add the Grape-DSL to the todos API.

## What are the relevant issue numbers?

Related to #22928

See merge request !6875

Extract project#update_merge_requests to its own worker from GitPushService

See merge request !6767

Closes #23337

Resolve "Fix missing Glossary link"

## What does this MR do?

Fixes broken links in University.

## What are the relevant issue numbers?

Closes #23332

See merge request !6880

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6019#note_16957939

Grapify system hooks API

## What does this MR do?

Add the Grape-DSL to the system-hook API.

## What are the relevant issue numbers?

Related to #22928

See merge request !6861

Add more info on the new CI permissions model

From discussion in issue https://gitlab.com/gitlab-org/gitlab-ce/issues/22484

See merge request !6843

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6019#note_16956860

Refactor merge requests revisions docs

See merge request !6878

- A system note now appears on every push
- Replace dashes with underscores in images

[ci skip]

Link to review apps example from docs

Put a link in the example project of the Review Apps in dynamic environments
and to the list of CI examples.

See merge request !6873

[ci skip]

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6019#note_16852207

Do not run before_script, artifacts, cache in trigger_docs job

Fixes

See merge request !6866

Replace unique keyframes mixin with specific keyframe animation names

## What does this MR do?
Replaces `unique-keyframes` mixin with `include-keyframes` mixin

## Are there points in the code the reviewer needs to double check?
Shouldn't be 👍🏻 

## Why was this MR needed?
Some users had GitLab hosted in a distributed environment that makes `unique-keyframes` a non-viable implementation. 
The randomized animation names from `unique-keyframes` was not being picked up by the different servers which resulted in 404 errors.

## Screenshots (if relevant)
None

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- Tests
  - [x] All builds are passing
- [x] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] 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)

## What are the relevant issue numbers?
Closes #22629

See merge request !6603