Show errors when rebase onto target branch fails in the UI

Closes #1774

See merge request gitlab-org/gitlab-ee!2780

Add push_rules is_sample partial index

See merge request gitlab-org/gitlab-ee!2966

Add new push rule to reject unsigned commits

Closes #3285

See merge request gitlab-org/gitlab-ee!2913

GitLab QA fix: Adjust license key add for GitLab 10.0 changes

See merge request gitlab-org/gitlab-ee!3059

[ci skip]

[ci skip]

Adds scheduled import jobs to the stuck import jobs detection worker.

See merge request gitlab-org/gitlab-ee!3055

When this rule is enabled, all the new commits that have not been signed
through GPG will be rejected.

Update issue_board.md

See merge request gitlab-org/gitlab-ee!3054

Move Deploy Board screenshot at the top of the page

See merge request gitlab-org/gitlab-ee!3053

EE Port of "Remove edit action for issues"

See merge request gitlab-org/gitlab-ee!3037

Part of https://gitlab.com/gitlab-org/gitlab-ce/issues/38487

Fix the lock-yourself-out prevention code and spec for Geo

Closes #3506

See merge request gitlab-org/gitlab-ee!3040

* master: (1365 commits)
  Fix i18n namespace typo
  Add doc regarding nested groups limitation
  Explain limitation for Jira dev panel integration on relative URL GL
  Fix syntax error
  Remove duplicated method, aligning to CE
  Resolve conflict
  We shouldn't delete existing user, otherwise
  Remove duplicated entry
  (EE) Create repositories via Gitaly
  Remove changelogs with invalid extensions
  Extend changelog checker to test file extensions
  Fix invalid changelog entries
  Manually add CHANGELOG entry for !13325
  Add static analysis job to find invalid YAML in changelogs
  Merge branch 'sh-fix-gitlab-qa-admin' into 'master'
  Adds a Gitaly n+1 notice to commit handling on access check
  Fix EE delta size check handling with annotated tags
  Move semi-linear merge strategy to CE area (mostly FE)
  Remove Project#merge_method accessors from EE side as we backported this to CE
  Update documentation for semi-linear history
  ...

# Conflicts:
#	spec/features/security/project/internal_access_spec.rb
#	spec/features/security/project/private_access_spec.rb
#	spec/features/security/project/public_access_spec.rb
#	spec/support/update_invalid_issuable.rb

Moves into .vue file

(cherry picked from commit 1eeaf62b12ba76818e7e38932e5d612f69e59ad0)

Refactoring after moving fast-forward merge to CE

See merge request gitlab-org/gitlab-ee!2937

Fix i18n namespace typo

See merge request gitlab-org/gitlab-ee!3046

Explain limitation for Jira dev panel integration on relative URL GL

See merge request gitlab-org/gitlab-ee!2876

CE upstream: Friday

Closes gitaly#601, gitaly#562, #3573, #3118, and gitlab-ce#38507

See merge request gitlab-org/gitlab-ee!3036