Migration to RxAndroidBle2

3.0.0-beta

• BREAKING Migrate Android implementation to RxAndroidBle2
  This might require the user to implement a global error handler https://github.com/ReactiveX/RxJava/wiki/What's-different-in-2.0#error-handling
  See more: https://github.com/Polidea/RxAndroidBle/wiki/FAQ:-UndeliverableException