* fix: remove returned Futures from switch.start
The proc `start` returned a seq of futures that was mean to be awaited by the caller. However, the start proc itself awaited each Future before returning it, so the ceremony requiring the caller to await the Future, and returning the Futures themselves was just used to handle errors. But we'll give a better way to handle errors in a future revision
Remove `switch.start` return type (implicit `Future[void]`)
Update tutorials and examples to reflect the change.
* Raise error during failed transport
Replaces logging of error, and adds comment that it should be replaced with a callback in a future PR.