Merge pull request #2 from matthieu-beteille/new-api

feat(api): update effects shape, now an array of maps

feat(combineReducers): support redux combineReducers function

now export a combineReducers function behaving similarly as redux's one, so you can now return
effects from reducers combined together into a main one.

feat(fx): create fx function

you now need to use the function fx(newState, Effects) from the package to retu

BREAKING CHANGE: no more _fx field, now use fx function

feat(api): state is now newState

when returning fx and state from the reducer the state should be in the newState field

build(build): try npm deployment