wip
Merge branch 'master' of https://github.com/juju/juju into 166-apiserver-common-authoriser-remove-getauthentity-method
gofmt
Issue #1357033: make a backups test more deterministic.
Merge pull request #525 from ericsnowcurrently/fix-1357033-broken-backups-test

Issue #1357033: make a backups test more deterministic.

Here is a solution to the failing test from [issue #1357033](https://bugs.launchpad.net/juju-core/+bug/1357033).  Incidentally, I took this basically verbatim from one of my outstanding PRs.
Add metadata for state backups.
Remove superfluous code and track backup origins.
Add an extra backup timestamp field and rename a file.
Fix docstrings.
errors.Errorf -> errors.Annotate
Fix a copy-and-paste docstring issue.
Test for the actual env ID rather than a bad regex.
archived -> stored
backup -> backups
Fix formatting.
Panic if we cannot find the hostname.
Fix some typos.
Clean up backups metadata test code.
Rename the mongo collection for backups metadata.
Use ConnSuite instead of StateSuite.