update minitest to 5.0 to get fix for .after_tests
TODOs update
Auto-convert Future#fail „message“ to FutureFailed.new(„message“) exception
Do not send Accept after Done or twice
Make sure there are no unresolved Futures
Make test sleep times shorter
When Timer is up Clock can call any method
Support timeouts in Future

Future#wait(timeout = nil) and Future#value(timeout = nil)
TimeOut all Futures in tests within 2sec if they are not resolved