Improve 'rake ci:migrate' error message when no backup is found

$ bundle exec rake ci:migrate
This will remove all CI related data and restore it from the provided backup.
Do you want to continue (yes/no)? yes

no backups found
The specified CI backup doesn't exist!

cc @ayufan @marin @JobV

This happen also to me, because the ci:migrate is looking for a tar file while your backup is probably a tar.gz

I didn't undestand if I miss some step of whatelse but I'm not able to migrate CI data to gitlab istance.

@claudyus No, if you update to final GitLab CI 8.0 it will create .tar backup.

Status changed to closed