Remove Java 8 targeting

combineLatest extensions for Observable and Flowable (ReactiveX#116)

* combineLatest extensions for Observable and Flowable

* jdk8

Merge branch 'sam-adapters' into 2.x

rename combineFunction to combiner

More operators for Observable<Single>, Flowable<Single>, etc. (Reacti…

…veX#101)

* add several more operators for Observable<Single>, Flowable<Single>, etc...

* remove import  io.reactivex.*

* rid plural maybes in operator name

* rid some operators targeting `Observable<Single>` and `Observable<Maybe>` and Flowable counterparts, out of scope

* update version to 2.0.0

remove `joinToString()` and `withIndex()` tests

set to new groupId

Wrap OnErrorNotImplementedException (ReactiveX#100)

remove withIndex() and joinToString()

RxKotlin 2.0 Release Candidate (ReactiveX#95)

* Dependencies updated

* Initial implementation of rxKotlin for rxJava2

* Code cleaning.
Code review related fixes.

* Whitespaces removed.

* gitignore update

* subscribers replaced by named args extension

* subscribeBy non-null params

* empty* methods removed
flowable extensions added
minor fixes

* dependencies updated

* subscribeBy method for Flowable

* tests updated

* minor tests refactoring

* * JoinToString method and tests ported from rxKotlin 1.0
* Subjects removed
* Operators added

* Minor formatting fix

* More formatting fixes

* Refactor "subscription" references to "disposable"

* refactor `flowable.kt` and `observable.kt` to match 1.x changes

* add `Flowable` support for operators

* update `single` to match 1.x changes

* rid Subject functions

* update readme to reflect `onComplete`

* Fix 2.x extension tests

* add Array<T>.toFlowable()

* update and fix compile errors for tests in 2.x

* move swtichOnNext()

* git commit -m 'refactor package domain to io.reactivex.rxkotlin'

* optimize imports