Update say to always flush the output after a puts

Buffer might not flush always re: https://stackoverflow.com/questions/63744814/puts-doesnt-flush-the-buffer-in-io-redirection-program

lib/highline.rb

@@ -380,6 +380,7 @@ def say(statement)
       output.flush
     else
       output.puts(statement)
+      output.flush #  Buffer might not flush always re: https://stackoverflow.com/questions/63744814/puts-doesnt-flush-the-buffer-in-io-redirection-program
     end
   end