0.20.2 (2015-08-07)
-----
* `ActorSystem` moved to `Actor::System` in Celluloid; that is reflected here.
* Only show `:debug` level of output if `$CEULLULOID_DEBUG` set to `true`.

0.20.1 (2015-07-15)
-----
* Refactored `Celluloid::Internals::CPUCounter`

0.20.0
-----
* Original release of new gem, extracted from `Celluloid`