Add 2017-04-11-inmemory-azure-entities-breaks-queue

[imbstack]

Just making this PR as an example for an rfc I'm about to write, but feel free to comment on it regardless!

[djmitche]

It seems like the root here is deploying a change that requires a config update, and forgetting to do that config update. Catching that in tests is good, but not always possible.

I'm not sure of an automated way to catch that -- basically someone has to observe, "this will require a config change", and then find a way to prevent deployment before that config change has been made. Maybe the easiest is, just make the config change right away?

[imbstack]

This wasn't actually missing config as you saw in taskcluster/taskcluster-queue/#163 after you wrote this note initially :p

Does that change your thoughts on it at all? Perhaps the action item that we did yesterday to make inMemory yell if you don't even pass in this key is enough?

[djmitche]

Yeah, I definitely mis-interpreted that. I think the inMemory change fixes the narrow cause of the issue, and that setting up a staging environment and test is the most comprehensive way to address the broader cause (issues in deployment not caught by testing). Both are already on the action-items list :)