Support `time-manager-0.3.*`

[sol]

Tests are failing with time-manager-0.3.* (be9b9c4).

I don't know what exactly makes time-manager-0.3.* incompatible with previous versions.

@kazu-yamamoto Can you help with fixing the tests?

[Yuras]

time-manager doesn't support non-threaded runtime, you just need to pass -threaded to tests: #573 (comment)

[sol]

Great, I will include this in #581.