QA: Sign in as an admin account when adding a license

See merge request gitlab-org/gitlab-ce!21657

properly wrap LICENSE file

[ci skip]

See merge request gitlab-org/gitlab-ce!21604

Adds the ability to use admin credentials to add a license so that when
testing an LDAP user on EE the LDAP user does not have to be an admin.

Admin credentials default to GDK's root user. Can be overriden via
ADMIN_USERNAME and ADMIN_PASSWORD environment variables.

Resolve "Changes in in-memory application settings in one spec can break another spec"

Closes #51268

See merge request gitlab-org/gitlab-ce!21638

Update karma: 2.0.4 -> ^3.0.0

See merge request gitlab-org/gitlab-ce!21593

add tooltip directive from gitlab-ui

See merge request gitlab-org/gitlab-ce!21522

Synchronize the default branch when updating a remote mirror

See merge request gitlab-org/gitlab-ce!21653

Migration specs may be missing a column necessary to create an ApplicationSetting
object, which causes the FakeApplicationSetting to be initialized. However, the
project selects a random repository storage via ApplicationSetting#pick_repository_storage,
which isn't present in the OpenStruct.

To workaround this issues, we add a pick_repository_storage method in
FakeApplicationSetting.

[CE] Make spec/lib/gitlab/import_export/all_models.yml EE-ready

Closes gitlab-ee#7471

See merge request gitlab-org/gitlab-ce!21544

Bump KaTeX version to 0.9.0

Closes #51065

See merge request gitlab-org/gitlab-ce!21625

Reset column information before running CommonMetricsImporter

Closes #51305

See merge request gitlab-org/gitlab-ce!21647

Enforce good commit messages using Danger

Closes #50003

See merge request gitlab-org/gitlab-ce!21527

Fix vertical alignment of text in diffs

Closes #48902

See merge request gitlab-org/gitlab-ce!21573

Closes #51065

This makes sure that newly created columns would be available when
migrating in one go.

Bump Sidekiq 5.1.3 to 5.2.1

See merge request gitlab-org/gitlab-ce!21624

Bump gitlab-shell to 8.3.1

See merge request gitlab-org/gitlab-ce!21648

docs: Correct YAML indentation

See merge request gitlab-org/gitlab-ce!21631

8.3.0 was tagged with the commit before the CHANGELOG.md and
version.rb bump, so this just fixes a harmless warning.

Add `duration` attributes to Jobs API docs

See merge request gitlab-org/gitlab-ce!21626

Add changelog to !21371

See merge request gitlab-org/gitlab-ce!21615