-str - Removes Source.unfoldInf

Motivation: Since it can be easily implemented inline on top of unfold

akka-stream/src/main/scala/akka/stream/javadsl/Source.scala

@@ -184,13 +184,6 @@ object Source {
   def unfoldAsync[S, E](s: S, f: function.Function[S, Future[Option[(S, E)]]]): Source[E, Unit] =
     new Source(scaladsl.Source.unfoldAsync(s)((s: S) ⇒ f.apply(s)))
 
-  /**
-   * Simpler [[unfold]], for infinite sequences.
-   */
-  def unfoldInf[S, E](s: S, f: function.Function[S, (S, E)]): Source[E, Unit] = {
-    new Source(scaladsl.Source.unfoldInf(s)((s: S) ⇒ f.apply(s)))
-  }
-
   /**
    * Create a `Source` that immediately ends the stream with the `cause` failure to every connected `Sink`.
    */