Deleting the calendar named /tasks/
is disallowed.
At least one additional calendar must exist (otherwise deletion is forbidden).
Everything else is super flaky. Creating a calendar works, but it is sometimes not available for a while (I've tested sleeping 10 seconds, but that's not enough).
Renaming a collection doesn't seem to have any effect.
Creating events in calendars doesn't seem to work; just an opaque 404.
Apparently the whole system operates in an "eventual consistency" mode.
If you create a calendar, it will show up, eventually. This is a pain for integration tests, since we need to sleep, sometimes for a long period of time, before we can check the result of operations.