RxJava 2 vs 3

There's no requirement on whether to use RxJava 2 or 3.
Note that this library uses RxJava 3 version internally and it will be added to your dependencies.

If you're using RxJava 2 you need to add a dependency to a compatibility module:

implementation 'com.github.vivid-money.elmslie:elmslie-rxjava-2:{latest-version}'

And use different classes:

RxJava 3 -> RxJava 2:
- ElmStore -> ElmStoreCompat
- Actor -> ActorCompat

The rest of the implementation stays the same