Test model factories and new error reporting tool

[Michael Cooper]

Hey all,

I've got two quick updates for you,

First, anyone who is working on Kitsune should know that we've removed all
the modelmakers (things like `question(title="what?", save=True)`) and
replaced them with FactoryBoy factories [1]. These do largely the same
thing, but have a bit less boilerplate and more powerful. Keep an eye out
for these when writing new tests.

One major change is that the new model factories have some "fuzzy"
behavior. Some fields have defaults that are randomly generated, which
means they could pass one test run and fail the next. If you see behavior
like this, check if you have any unstated assumptions

[1]: https://factoryboy.readthedocs.org/en/latest/

The second big change (and this applies mostly to the core devs) is that we
aren't using Errormill anymore. Errormill is going away, so we've migrated
to a new version of Sentry that is run by CloudOps. The url for that is
https://sentry.prod.mozaws.net/operations/teams/sumo/ . You should all
have gotten emails inviting you to make accounts. If not, let me know and
we can get you fixed up.

CloudOps Sentry is a lot newer than Errormill, so we are getting some new
features, and things are a bit different. It looks nice though, so I'm
excited.