Support Backup 5.0.0

[Scott M Likens]

It is likely going to be one of the last releases of the Backup gem; beta 1 and 2 are already out.

Kind of sad it feels like with the backup gem going away this cookbook has less reason to get work on it :(

https://github.com/backup/backup/issues/851

I'll likely leave in features being deprecated so that way people who pick an older version can still use it.