Build coroutines version rather than Rx, to reduce method count and simplicity

[mochadwi]

Build coroutines version rather than Rx, to reduce method count and simplicity

[Drjacky]

Thanks for your suggestion, but the purpose of the article and this sample project has been something else from the beginning; Implementing MVVM with Clean Architecture approach together.
Maybe someday, I'll create another article and sample project which explain step-by-step how to migrate from Rx to Coroutine on another branch.