Auto-corrected with Rubocop

There are also minor changes to keep the Rails generated files
similar to when generating a new Rails 6 application

grape_logging was upgraded to fix deprecation messages related to
ActionDispatch::Http::ParameterFilter

Rails 6 now adds the nonce to style-src by default. We disable
this because we still have a lot of code that set inline styles
and we need 'unsafe-inline'

* updates Gemfile
* uses Rails 5 unless explicitly disable

* updates Gemfile
* uses Rails 5 unless explicitly disabled

* update-rubocop:
  Use stable gitlab-styles and eliminate offenses
  Updates from `rubocop -a`
  Update rubocop to get rid of a warning in other MR

Merge branch 'master' into non-interactive-aws-install

Conflicts:
	doc/installation.md

Fix merge mess in installation.md

Simplified gitolite handle logic
Stubn over monkeypatch
Stub only specific methods in Gitlab:Gitolite
Moved grach auth to lib
added specs for keys observer
removes SshKey role