Add valle.
Higher RUBY_GC_MALLOC_LIMIT.

According to http://discuss.samsaffron.com/t/demystifying-the-ruby-gc/81,
> Every rails app should have a higher malloc limit. The default is too
> small, this tiny default means that many Rails apps in the wild are
> getting zero benefit from the faster "lazy sweep" algorithm implemented
> in Ruby 1.9.3. Further more, low malloc limits mean that the GC runs way
> too often. Typical Rails requests will regularly allocate a couple of
> megs of RAM.
Add 'rack-mini-profiler' gem.