Simple Stack 2.3.0

Simple-Stack 2.3.0 (2020-02-27)

• CHANGE: Remove dependency on android.support.annotation.*. With that, there should be no dependency from the library on either android.support.* or androidx.*.

Replaced it using javax.annotation.Nullable and javax.annotation.Nonnull provided by api("com.google.code.findbugs:jsr305:3.0.2").

• UPDATE: state-bundle is updated to 1.3.0 (Remove dependency on android.support.annotation.*, replace with javax.annotation.*).

With these changes, Jetifier should no longer be needed when using Simple-Stack.