Bring back --future option

bin/github-pages

@@ -64,6 +64,7 @@ Mercenary.program(:"github-pages") do |p|
     c.option 'verbose', '--verbose', 'Verbose logging'
     c.option 'source', '--source DIR', 'From where to collect the source files'
     c.option 'destination', '--destination DIR', 'To where the compiled files should be written'
+    c.option 'future', '--future', 'Publishes posts with a future date'
 
     c.action do |_, options|
       Jekyll::Commands::Build.process(options)