soveran/micromachine

This release adds the ability to pass arbitrary payloads from `trigger` to callbacks. Check [this thread](https://github.com/soveran/micromachine/pull/41) for more information. The major version bump signals the possible backward incompatibility due to the fact that the arity of the callbacks was changed from one to two. If blocks are used for callbacks, then code using previous versions of `MicroMachine` remains compatible. On the other hand, if lambdas or methods were used then the code has to be adapted.