Group clusters should not allow Project Namespace so don't show that
field input too

Currently cluster_health is only available for Project level clusters
because we haven't figured out how to install Prometheus for a Group of
projects.

Based on BE reviewer feedback

As the frontend is still in progress and other related backend is still
in prgress we need a feature flag to turn off Group Clusters.

These applications will need further work in future issues to enable
them to work with groups of projects.

Remove the requirement to have actual_namespace before using kubeclient.

- Add pages javascripts to intialize clusters for group pages

- Move specs asserting gcp specific validations from controller into
UpdateService spec

- Also teach Clusters::ApplicationController about groups

As this is the only item in this menu, make Kubernetes the link for the
sidebar item too.

- maintainer for group can read, create, update, and admin cluster
- project user, at any level, cannot do anything with group cluster

CE upstream - 2018-11-09 14:21 UTC

See merge request gitlab-org/gitlab-ee!8382

Add e2e test of push via HTTP via Git protocol v2

See merge request gitlab-org/gitlab-ce!22925

Fixing failure due to comment filters

Closes gitlab-org/quality/nightly#35

See merge request gitlab-org/gitlab-ee!8376

CE upstream - 2018-11-09 12:21 UTC

See merge request gitlab-org/gitlab-ee!8381

Resolve "Vulnerability modal discrepancies on Group Security Dashboard"

Closes #8342

See merge request gitlab-org/gitlab-ee!8360

Remove created_at from WikiPage

See merge request gitlab-org/gitlab-ce!22905

Where GSP is the group security dashboard

where GSD is Group Security Dashboard
- Adds the "learn more" link
- Fixes a bug that renders [] for empy link lists
- Adds the Class field
- Tests for the above

CE upstream - 2018-11-09 11:21 UTC

See merge request gitlab-org/gitlab-ee!8380

Improve the Review Apps documentation a bit

See merge request gitlab-org/gitlab-ce!22910