add tests with dependent destroy

add tests with dependent destroy

add tests

add tests to projects spec

update it title  and remove let

update it title  and remove let

remove changes after rebase

remove changes after rebase

update changelog

This moves tracking of the pushes since the last Git GC from PostgreSQL
to Redis. This reduces the number of writes on the "projects" table.
This in turn reduces the vacuuming overhead.

The lease used for incrementing the counter has been removed. This lease
was mostly put in place to prevent high database load but this isn't
needed anymore due to the counter now being stored in Redis.

Fixes gitlab-org/gitlab-ce#22125

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/21823

# Conflicts:
#	lib/gitlab/github_import/importer.rb

MySQL could not have support for millisecond precision, depends on the MySQL version 
so we just create issues in different seconds in a deterministic way

Fixes failed builds such as https://gitlab.com/gitlab-org/gitlab-ce/builds/3919501

Use NotificationSetting::EMAIL_EVENTS for params

Sidekiq async tasks were being run after project namespaces were deleted. Use
Sidekiq in fake mode to prevent this from Sidekiq tasks from being enqueued
in the first place.

Closes #21723

Fix show template (missing tr)
Separate exercise/verify

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>