[BUG] Unnecessarily verbose asyncio-related messages after termination

[pseusys]

When a tutorial launched in interactive mode or test is interrupted by user request (e.g. Ctrl + C), random amount of different log messages is written to console.
These are messages related to asyncio: unawaited coroutines, interrupted tasks, etc.
I don't think that's desired behavior, in fact that is annoying and may mislead user into thinking that he encountered a bug.

Any help and ideas on removing these messages (or just replacing them with something nice like "Framework terminated successfully!") will be greatly appreciated.