Reminder: run a manual upgrade when writing upgrade steps

[Tim Penhey]

Hi folks,

The CI blocker earlier today was due to a branch from Onyx.  We had an
upgrade step that added a field to the user document so we can make sure
we had case insensitive user names.

However even though all the unit tests passed, a manual upgrade test
wasn't performed.  If we did do one, we would have caught this earlier.

This is a reminder to all people writing upgrade steps, and to all
reviewers where you see an upgrade step being changed or added to in the
branch.

Developers, please do a manual upgrade check. Even just using the local
provider is normally enough to kick the tires and notice serious issues.

Reviewers, please ask the developers if they have done a manual upgrade
test, and don't approve it until they have :-)

Sorry for any inconvenience that this caused.  The fix landed this
morning and I have confirmed that the upgrade CI jobs are passing again.

Cheers,
Tim