Replace deprecated exists call

Author: wolfsblu

src/neo.rb

@@ -218,15 +218,15 @@ def initialize
 
     def add_progress(prog)
       @_contents = nil
-      exists = File.exists?(PROGRESS_FILE_NAME)
+      exists = File.exist?(PROGRESS_FILE_NAME)
       File.open(PROGRESS_FILE_NAME,'a+') do |f|
         f.print "#{',' if exists}#{prog}"
       end
     end
 
     def progress
       if @_contents.nil?
-        if File.exists?(PROGRESS_FILE_NAME)
+        if File.exist?(PROGRESS_FILE_NAME)
           File.open(PROGRESS_FILE_NAME,'r') do |f|
             @_contents = f.read.to_s.gsub(/\s/,'').split(',')
           end