Promises are now not being resolved within the same tick, so give
another tick for the UI to update after all the HTTP calls have
flushed through. This is fairly terrible, but I can't immediately
see a better way of doing this.
The 'loading' tests only worked when run with the other tests and
failed if you just ran the file by itself, because the skin was
loading in the 'joining' tests, but not here.
1. fix the 'Clean load' tests which had been broken by
https://github.com/matrix-org/matrix-react-sdk/pull/399: make sure we clear
localStorage between tests.
2. Test the session rehydration properly by setting the localStorage rather
than setting up the MatrixClientPeg before loading the app.
3. Add some tests for the auto-guest-registration flows.
David Baker