check wiki, group wiki, snippet, and design repos with rake task gitlab:git:fsck

Proposal

The documentation currently states:

Check all GitLab repositories

This task loops through all repositories on the GitLab server and runs the integrity check described previously.

These:

• Snippet repositories
• Group wiki repos

do not appear to be checked by the repo fsck rake task which only seems to loop over project.repository.

Additionally:

• project wiki repos
• project design repos

These are .wiki and .design along side the project repo, but based on the output of the following and the output from the rake task, it doesn't seem like they're checked.

Project.find_each(batch_size: 100) do |project|
  pp project.repository.disk_path
end

Updated to reflect the correct status of pool repositories.