If CE master is ahead of EE master, and the CE branch
was forked from CE master, then the CE branch would
contain a lot of changes which aren't presented in EE master,
therefore they're not presented in EE branch, either.

In this case, we need to remove the commits from CE master
which aren't merged into EE yet. So we want to rebase CE branch
onto CE/EE merge base, with ce_fetch_base and ce_fetch_head,
where ce_fetch_base is the merge base of CE master and CE branch,
and ce_fetch_head is the original HEAD of CE branch.

This should make sure there's no extra commits involved.

The only way it could fail would be conflicts during rebase,
which ideally should not happen at all. This doesn't mean
it's impossible to happen, but given the reason we make the CE branch,
it should only contain minimum changes from EE to CE, which shouldn't
conflict.

Let's try this and see and investigate if conflicts happen.

Remove `features/group_active_tab.feature`

See merge request gitlab-org/gitlab-ee!5554

Update group menu position based on 10.x UI changes.

See merge request gitlab-org/gitlab-ee!5544

Replace the `groups_management.feature` spinach test with an rspec analog

See merge request gitlab-org/gitlab-ee!5516

Replace the `group_hooks.feature` spinach test with an rspec analog

See merge request gitlab-org/gitlab-ee!5515

Port to EE: Include documentation about STAGING_ENABLED variable for AutoDevops

See merge request gitlab-org/gitlab-ee!5536

This commit removes redundant spinach spec: features/group_active_tab.feature

[ci skip]

[ci skip]

Geo: Exclude expired job artifacts from syncing and counts

Closes #5357

See merge request gitlab-org/gitlab-ee!5380

CE upstream - 2018-05-02 09:27 UTC

See merge request gitlab-org/gitlab-ee!5540

EE-Port for Emoji Sprites Optimisation

See merge request gitlab-org/gitlab-ee!5538

Resolve "The `ee-specific-lines-check` should ignore files under `ee/`"

Closes #5856

See merge request gitlab-org/gitlab-ee!5549

Adding initial outline of pgbouncer documentation

Closes omnibus-gitlab#2649

See merge request gitlab-org/gitlab-ee!5351

Make ee/spec/features/admin/admin_sends_notification_spec.rb more reliable

See merge request gitlab-org/gitlab-ee!5547

Unify app/assets/javascripts/clusters/components/application_row.vue with CE

See merge request gitlab-org/gitlab-ee!5545

reliable

Merge branch '5841-geo-basesyncservice-should-prune-the-geo-temporary-directory-before-fetching' into 'master'

Resolve "Geo: BaseSyncService should prune the @geo-temporary directory before fetching"

Closes #5841

See merge request gitlab-org/gitlab-ee!5543

Skip master for EE-specific check

See merge request gitlab-org/gitlab-ee!5542

* Add link to components in HA README
* Fix typo in pgbouncer page

master is a special case that CE master is not crafted toward
EE master, thus it could be ahead of EE master. In this case
we should compare with the merge-base, but that could make
the code unnecessarily complex and is not worth the effort.

# Conflicts:
#	app/views/groups/_group_admin_settings.html.haml
#	spec/requests/api/runner_spec.rb

[ci skip]

Replace the `admin/emails.feature` spinach test with an rspec analog

See merge request gitlab-org/gitlab-ee!5513

Replace the `admin/push_rules.feature` spinach test with an rspec analog

See merge request gitlab-org/gitlab-ee!5512

Resolve "Create a new job to check that EE-specific lines are minimal"

Closes #5682

See merge request gitlab-org/gitlab-ee!5404

Replace the `project/source/markdown_render.feature` spinach test with an rspec analog

See merge request gitlab-org/gitlab-ce!18525

[Rails5] Fix spec/services/applications/create_service_spec.rb

See merge request gitlab-org/gitlab-ce!18665