Set less strict flay option for now

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

lib/tasks/flay.rake

 desc 'Code duplication analyze via flay'
 task :flay do
-  output = %x(bundle exec flay app/ lib/gitlab/)
+  output = %x(bundle exec flay --mass 30 app/ lib/gitlab/)
 
   if output.include? "Similar code found"
     puts output