Fix poll loading in vumi_app.js (it's already JSON).
Fix test config require function.
Log events as we did before the migration to sandbox toolkit v02.
Check that switched to state messages are logged when processing messages.
Remove broken poll state from dummy polls (these always cause the poll to fail and aren't useful as generic test data).
Mark poll data as not JSON when setting up tests.
Merge branch 'feature/issue-913-fix-poll-loading' into develop