Upgrade Workhorse to 4.0.0

See merge request gitlab-org/gitlab-ce!17606

Resolve: Modal and banner designs for project label and project milestone promotion

Closes #41895

See merge request gitlab-org/gitlab-ce!17197

Minor fixes in API doc

See merge request gitlab-org/gitlab-ce!17602

Use Project#full_name instead of name_with_namespace

See merge request gitlab-org/gitlab-ce!17601

Make git push mandatory

See merge request gitlab-org/gitlab-ce!17565

Remove wrong assumption about Runners cache GC

See merge request gitlab-org/gitlab-ce!17598

Merge branch 'sh-fix-otp-backup-invalidation-10-5' into 'master'

See merge request gitlab/gitlabhq!2349

Move Ruby endpoints to OPT_OUT

See merge request gitlab-org/gitlab-ce!17561

Backport of "Geo: Ignore remote stored objects when calculating counts"

See merge request gitlab-org/gitlab-ce!17581

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

Merge branch 'pages-6-1-gitlab-10-5' into 'master'

See merge request gitlab/gitlabhq!2350

add nginx_status monitoring details

See merge request gitlab-org/gitlab-ce!17596

Part of: gitlab-org/gitaly#476

Part of: gitlab-org/gitaly#476

Part of: gitlab-org/gitlab-ce!17561

Part of: gitlab-org/gitaly#540

Part of: gitlab-org/gitaly#546

Part of: gitlab-org/gitaly#779

Part of: gitlab-org/gitaly#541

Part of gitlab-org/gitaly#324

Use persisted/memoized value for MRs sha's instead of doing git lookups

See merge request gitlab-org/gitlab-ce!17555

Add discussion API

See merge request gitlab-org/gitlab-ce!17510

Resolve "Update language about version check in admin settings and docs"

Closes #43486

See merge request gitlab-org/gitlab-ce!17535

Add CommonMark markdown engine

See merge request gitlab-org/gitlab-ce!14835

Keep track of projects a user interacted with

Closes #43460

See merge request gitlab-org/gitlab-ce!17327

Update gitlab-pages version (GitLab 10.5)

See merge request gitlab/gitlabhq!2330

(cherry picked from commit 2c6ce6ff3efe4e5a7a6dc9a79a48e9c5ebad1a29)

15f8d4a6 Update gitlab-pages version

Ensure that OTP backup codes are always invalidated - 10.5 port

See merge request gitlab/gitlabhq!2324

https://gitlab.com/gitlab-org/gitlab-ce/issues/41249#note_60629323

Show plugins list on system hooks page

Closes #40812

See merge request gitlab-org/gitlab-ce!17518

* adds basic discussions API for issues and snippets
* reorganizes notes specs (so same tests can be used for all noteable types - issues, MRs, snippets)

Unify deployment_platform interface with EE

See merge request gitlab-org/gitlab-ce!17594

Fix group boards migration name

See merge request gitlab-org/gitlab-ce!17592