This helper module adds a few assertion methods that can be used across
specs that test our custom autocomplete behaviours

They're used here in a few updating permissions tests, and will be used
in the next commit in new inviting users tests when adding autocomplete
to the organisation field

This upgrades the organisations field in the page for inviting a new
user to use the accessible autocomplete module (with progressive
enhancement)

This allows us to get away from testing this custom JavaScript behaviour
in multiple integration tests. We might want to test that everything
works without the add/add and finish buttons being present (it does)