Reduce progress bar noise during brakeman run

lib/tasks/brakeman.rake

@@ -2,7 +2,7 @@ desc 'Security check via brakeman'
 task :brakeman do
   # We get 0 warnings at level 'w3' but we would like to reach 'w2'. Merge
   # requests are welcome!
-  if system(*%W(brakeman --skip-files lib/backup/repository.rb -w3 -z))
+  if system(*%W(brakeman --no-progress --skip-files lib/backup/repository.rb -w3 -z))
     puts 'Security check succeed'
   else
     puts 'Security check failed'