Before this change, trying to setup dev environment could be tried
without having at least one Gitaly running. Cloning the repositories
would fail, but not stop the setup.

Given this would lead to an inconsistent state, a check was added if we
could connect to the server.

Output when it fails:

```
$ rake dev:setup
Failed to connect to Gitaly...
Error: 14:Connect Failed
```

Ensure that cached_markdown_version is handled correctly for CommonMark

See merge request gitlab-org/gitlab-ce!18431

[Rails5] Add `safe_params` helper

See merge request gitlab-org/gitlab-ce!18241

This reverts merge request !18399

Fix link in Security Developer Workflow.md

See merge request gitlab-org/gitlab-ce!18445

Email notification on issue due date

Closes #27500

See merge request gitlab-org/gitlab-ce!17985

Resolve "Make a Rubocop that forbids returning from a block"

Closes #42889

See merge request gitlab-org/gitlab-ce!18000

Resolve "Concurrent requests to api/v4/jobs/request cause DB locks on ci_builds_metadata table"

Closes #45456

See merge request gitlab-org/gitlab-ce!18428

Resolve "Using goldiloader results in Ci::RegisterJobService#execute spending a lot of time eager loading a lot of associations"

See merge request gitlab-org/gitlab-ce!18439

Resolve "Time estimate system notes can be confusing"

Closes #40402

See merge request gitlab-org/gitlab-ce!18326

Docs assign labels to subgroups

See merge request gitlab-org/gitlab-ce!18438

Fix Markdown typo in Web IDE docs

See merge request gitlab-org/gitlab-ce!18443

Fix `Trace::HttpIO` can not render multi-byte chars

Closes #44981

See merge request gitlab-org/gitlab-ce!18417

Improve jobs queuing time metric (fixed version)

Closes #45205

See merge request gitlab-org/gitlab-ce!18283

Return nil on empty path

Closes gitaly#1115

See merge request gitlab-org/gitlab-ce!18430

[Rails5] Remove `as` keyword from `Gitlab:Ci:Trace:Stream.delegate :valid?`

See merge request gitlab-org/gitlab-ce!18270

Fix size and position for fork icon

Closes #42582

See merge request gitlab-org/gitlab-ce!18399

As seen in https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/5399

Remove ahead/behind graphs on project branches on mobile

Closes #42543

See merge request gitlab-org/gitlab-ce!18415

Docs: update Web IDE > CE (10.7)

See merge request gitlab-org/gitlab-ce!18433

Docs: add product badges to docs

Closes #42631

See merge request gitlab-org/gitlab-ce!18408

Move Gitaly RefExists check to OPT_OUT

Closes gitaly#401

See merge request gitlab-org/gitlab-ce!18333

add initial dev task template for working on a security issue

Closes gitlab-org/release/docs#9

See merge request gitlab-org/gitlab-ce!18133

Update to Git 2.16.3 in doc/install/installation.md

See merge request gitlab-org/gitlab-ce!18434

Add QA tests for protected branches

See merge request gitlab-org/gitlab-ce!18301

Ignore `locale/gitlab.pot` in ee_compat_check

See merge request gitlab-org/gitlab-ce!18424

Remove ambiguity when forking a project to a user's namespace

See merge request gitlab-org/gitlab-ce!18426

and also make sure that if a field is saved, then the existing cache version is maintained or only upgraded to the version with the same markdown engine.