Bugs and regression triage and prioritization process

See merge request gitlab-org/gitlab-ce!20623

Reorganize variables.scss, Part 1

See merge request gitlab-org/gitlab-ce!21118

Resolve "Add missing i18n strings to issue boards."

Closes #50063

See merge request gitlab-org/gitlab-ce!21081

Merge branch '47752-buttons-on-new-file-page-wrap-outside-of-container-for-long-branch-names' into 'master'

Resolve "Buttons on new file page wrap outside of container for long branch names"

Closes #47752

See merge request gitlab-org/gitlab-ce!21015

Resolve "Group Overview list items layout regression"

Closes #50176

See merge request gitlab-org/gitlab-ce!21124

Add frozen_string_literal to recently-added files from the community

See merge request gitlab-org/gitlab-ce!21132

Resolve "Consider enforcing the use of the new Ruby safe navigation operator (aka `&.`)"

Closes #27884

See merge request gitlab-org/gitlab-ce!21140

Resolve ""Block user" section in admin area has wrong styling"

Closes #50126

See merge request gitlab-org/gitlab-ce!21095

Resolve "Clarify `List user projects` API Endpoint"

Closes #50174

See merge request gitlab-org/gitlab-ce!21121

Signed-off-by: Rémy Coutable <remy@rymai.me>

Reduce differences between CE and EE code base in reports components

See merge request gitlab-org/gitlab-ce!21128

CE Port of Protected Environments backend

See merge request gitlab-org/gitlab-ce!20859

Resolve "CI: cancel/skip a job in "created" state using a button"

Closes #48320

See merge request gitlab-org/gitlab-ce!20635

port "Resolve "Mirroring interface improvements""

See merge request gitlab-org/gitlab-ce!20837

Resolve "GFM : provide 'project' reference in comment"

Closes #28930

See merge request gitlab-org/gitlab-ce!20285

docs: removed duplicate `git_ssh_url` field from build event example

See merge request gitlab-org/gitlab-ce!21123

Enable frozen string in rest of app/models/**/*.rb

See merge request gitlab-org/gitlab-ce!21129

Rails5 fix specs duplicate key value violates unique constraint…

See merge request gitlab-org/gitlab-ce!21119

Partially addresses #47424.

Bump pry to 0.11.3; pry-byebug to 3.4.3

See merge request gitlab-org/gitlab-ce!21122

Previously the key `git_ssh_url` was listed twice in the example payload of an Build Event web hook.

Add mock data for spam logs

Closes gitlab-development-kit#387

See merge request gitlab-org/gitlab-ce!21117

Update GitLab Shell to v8.1.1 to fix regressions

See merge request gitlab-org/gitlab-ce!21120

Rails5 fix specs duplicate key value violates unique constraint 'index_gpg_signatures_on_commit_sha'

Closes https://gitlab.com/gitlab-org/gitlab-development-kit/issues/387

Disable danger in preparation branches

See merge request gitlab-org/gitlab-ce!21112

Most of these validations don't apply to preparation branches and they
cause a lot of noise in the merge request. Therefore disabling danger
when the branches look like branches that could be for a preparation MR.