Update rails version to 3.2.5

Created by: avakarev

closes #883 closes #882

582 examples, 0 failures

And I've got 2 deprecation warnings about "link_to_function" in app/views/merge_requests/_commits.html.haml:12

It will removed from Rails 4.0, details here: https://gist.github.com/rails/rails/pull/5922