Add troubleshooting section to Slack Notification Service

See merge request gitlab-org/gitlab-ce!24339

Fix bug that caused Suggestion Markdown toolbar button to insert snippet with leading +/-/<space>

See merge request gitlab-org/gitlab-ce!24568

Add Avatar in the settings sidebar

Closes #56582

See merge request gitlab-org/gitlab-ce!24515

All review jobs should share the same only & except

Closes #56707

See merge request gitlab-org/gitlab-ce!24579

Fix serverless.yml template indentation

See merge request gitlab-org/gitlab-ce!24548

Avoid installing Bundler 2.0 or higher on source-based install

Closes #55979

See merge request gitlab-org/gitlab-ce!24502

Rename entrypoint for clusters update/edit page

Closes #56715

See merge request gitlab-org/gitlab-ce!24583

Upgrade Prettier to v1.16

See merge request gitlab-org/gitlab-ce!24581

Upgrade babel to v7.3

See merge request gitlab-org/gitlab-ce!24573

Add domain field into Clusters::Cluster

See merge request gitlab-org/gitlab-ce!24368

For the stake of standardizing, I've switched the ssl debugging to use
the Rails console rather than a Ruby script file.

Offer more explanation regarding the ssl-test script and how it's used.

Use relative link rather than URL

Adds inter-service OpenTracing propagation

See merge request gitlab-org/gitlab-ce!24239

fix(labels): Move the primary button out of breadcrumbs and into the project section

Closes #56558

See merge request gitlab-org/gitlab-ce!24516

Upgrade gitlab-workhorse to 8.1.0

See merge request gitlab-org/gitlab-ce!24571

Improve localTimeAgo rendering

Closes #56327

See merge request gitlab-org/gitlab-ce!24389

This is the 1st step for moving Auto DevOps domain into cluster
settings, whether is project or group.

Related to https://gitlab.com/gitlab-org/gitlab-ce/issues/52363

Removes factories on Cluster background migration

See merge request gitlab-org/gitlab-ce!24536

Hashed Storage: `AfterRenameService` was not renaming Pages or Uploads folder on legacy storage

Closes #56636

See merge request gitlab-org/gitlab-ce!24526

Refactor Sidekiq workers to reduce differences between CE and EE

See merge request gitlab-org/gitlab-ce!24466

Edits to issues CSV import docs

See merge request gitlab-org/gitlab-ce!24554

This change allows the GitLab rails and sidekiq components to receive
tracing spans from upstream services such as Workhorse and pass these
spans on to downstream services including Gitaly and Sidekiq.

This change will also emit traces for incoming and outgoing requests
using the propagated trace information. This will allow operators and
engineers to view traces across the Workhorse, GitLab Rails, Sidekiq and
Gitaly components.

Additional intra-service instrumentation will be added in future
changes.

Before, diff file `higlighted_diff_lines`/`parallel_diff_lines` and
diff discussion `truncated_diff_lines` were inconsistent: `text` and
`rich_text` on the latter included the leading +/-/<space> character,
like on the backend, while the former had no `text` and its `rich_text`
had dropped this char.

This resulted in a bug when the suggestions feature expected these diff
line objects to be identical in format and thus interchangeable, which
was not the case.

Changed the Caching of User Avatars to be public and to 5 minutes

See merge request gitlab-org/gitlab-ce!24546

https://babeljs.io/blog/2019/01/21/7.3.0

Resolve "When ref is ambiguous, `CreatePipelineService` raises an error"

Closes #55966

See merge request gitlab-org/gitlab-ce!24437

Make favicon tests more fault resistent

Closes #50527

See merge request gitlab-org/gitlab-ce!22686

'Populate cluster kubernetes namespace' was using factories for their
specs. According to our documentation (see spec/migrations/readme.md),
we should use table helper to create a temproary ActiveRecord::Base
derived model for a table.