For the last year and a half I have been doing some code reviewing at work. And I noticed that most of the time the tasks are reopened because of very small things, like text formatting, variable naming and so on. This could've been prevented just by using Perl::Critic for example. Unfortunaly the code base is big, and that would take a lot of time. That's why I have written https://kritika.io which makes the analysis incrementally and is damn easy to integrate with GitHub and Travis CI (or anything else actually). The service is in beta right, but i have been using it secretly for the last 5 months anyway. It is useful for me, maybe it can be useful for you too.