[EE] Remove the User#is_admin? method

See merge request !1615

Update rubocop-rspec 1.12.0 -> 1.15.0

See merge request !1609

EE port of "Start discussion"

See merge request !1556

Update droplab to webpack version ee

See merge request !1608

Port of button-capitalisation for EE

See merge request !1590

EE port of "Copy diff file path as GFM"

See merge request !1589

Add user cohorts table to admin area

Closes gitlab-ce#29551

See merge request !1545

Make deploy board be visible by default

Closes #2106

See merge request !1595

Merge remote-tracking branch 'origin/master' into update-trace-handling-code

See merge request !1580

Service desk usage ping

Closes #1706

See merge request !1588

removes the duplicate sum of lfs objects

Closes #2055

See merge request !1599

Service Desk FE updates v1

See merge request !1604

Remove wrong user email from CI variables example output

See merge request !1606

[ci skip]

Merge branch '27790-periodically-save-last-activity-date-data-from-redis-to-the-database-hscan' into 'master'

[Improved] Periodically save last activity date data from Redis to the database

See merge request !1597