Added 'experimentatal' warnings to Actress factory methods.

Author: jdantonio

lib/concurrent/actress.rb

@@ -42,6 +42,7 @@ def on_message(message)
     # @param block for actress_class instantiation
     # @param args see {.spawn_optionify}
     def self.spawn(*args, &block)
+      warn '[EXPERIMENTAL] A full release of `Actress`, renamed `Actor`, is expected in the 0.7.0 release.'
       if Actress.current
         Core.new(spawn_optionify(*args).merge(parent: Actress.current), &block).reference
       else
@@ -51,6 +52,7 @@ def self.spawn(*args, &block)
 
     # as {.spawn} but it'll raise when Actor not initialized properly
     def self.spawn!(*args, &block)
+      warn '[EXPERIMENTAL] A full release of `Actress`, renamed `Actor`, is expected in the 0.7.0 release.'
       spawn(spawn_optionify(*args).merge(initialized: ivar = IVar.new), &block).tap { ivar.no_error! }
     end