Fix cache issues with status updates.

Review Request #8856 — Created March 28, 2017 and submitted — Latest diff uploaded

Information

Review Board
release-3.0.x
bc7dd74...

Reviewers

If a status update is updated (for example, going from starting -> done)
without an associated review, timestamps wouldn't be updated such that the
review request ETag would change. To fix that, I've added auto_now to the
timestamp field so that it gets updated whenever the status update is changed,
and fixed the ETag calculation to look at all the status update timestamps.

Posted a review and had Review Bot start. Saw that the initial status update
was marked as "starting", and then reloaded. Whereas before it would still show
as starting (without a shift+reload), now it showed that the tool ran
sucessfully.