Revert "Revert "Merge pull request #530 from ericsnowcurrently/backups-storage""

This reverts commit 68c71ec48f16eac6f8aff2a66496afb148ec95c6.
Merge pull request #611 from ericsnowcurrently/backups-storage

Un-revert PR #530

This reverts commit 68c71ec48f16eac6f8aff2a66496afb148ec95c6.  It simply re-applies a93e1df919450377b6dab707552582fd604cd8cf.
Merge branch 'master' of https://github.com/juju/juju