Merge branch 'brakeman-level'

Conflicts:
	lib/tasks/brakeman.rake

lib/tasks/brakeman.rake

 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))
     puts 'Security check succeed'
   else