1.2.0

• Rewrite the Android-specific schedulers (main thread or custom) to greatly reduce allocation and
  performance overhead of scheduling work.
• HandlerScheduler.create has been deprecated in favor of AndroidSchedulers.from(Looper) as
  a Looper is the actual mechanism of scheduling on Android, not Handler.
• Fix: Correct the behavior of AndroidSchedulers.mainThread() to only invoke the registered
  RxAndroidSchedulersHook for creating the main thread scheduler and to cache the result instead
  of invoking it every time. This behvior change eliminates a performance overhead and brings
  behavior in line with RxJava. If you were relying on the ability to change the main thread
  scheduler over time (such as for tests), return a delegating scheduler from the hook which allows
  changing the delegate instance at will.
• RxJava dependency now points at v1.1.4.
• RxAndroidPlugins.reset() is now marked as @Experimental to match the RxJava method of the
  same name and behavior.