I mistakenly assumed that not setting the cookiejar argument when
creating a webtest TestApp would mean that no cookies would be retained
between requests, but that's wrong. If you don't pass a cookiejar, it
just automatically creates one for you. Because of this, logged-out
webtests would end up being logged-in after any test logged in.
This reduces the webtest_loggedout fixture's scope to function-level so
that it will be re-initiated on every test instead. It also stops
passing a cookiejar for the logged-in webtest, since that's unnecessary.
Deimos