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.

Fix label item height when no desc

Closes #47928

See merge request gitlab-org/gitlab-ce!21106

Moves reports components to the reports folder

See merge request gitlab-org/gitlab-ce!21069

Add default avatar to group

Closes #28582, #36840, #35408 et #40409

See merge request gitlab-org/gitlab-ce!17271

Documentation + rubocop for checking that foreign key constraints require an index

Closes #49789

See merge request gitlab-org/gitlab-ce!20964

Allow the Web IDE to open empty merge requests

Closes #48166

See merge request gitlab-org/gitlab-ce!21102

Fix label item height when no desc

Closes #47928

See merge request gitlab-org/gitlab-ce!21106

Resolve "Job Failed #87997478"

Closes #50153

See merge request gitlab-org/gitlab-ce!21111

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

Phase 2: #47282 Improving Contributor On-Boarding Documentation

See merge request gitlab-org/gitlab-ce!20682

Resolve "docs update api for usage with an array of hashes"

Closes #49821

See merge request gitlab-org/gitlab-ce!20952

Backport of EE "catch entering username as an email instead of returning a 500 error"

See merge request gitlab-org/gitlab-ce!21085

Add Bitbucket Server importer docs

See merge request gitlab-org/gitlab-ce!21097

Update doc/integration/oauth_provider.md

See merge request gitlab-org/gitlab-ce!21093

Docs: fix ee-conflict in bulk editing

See merge request gitlab-org/gitlab-ce!21091