Prepare for upgrade to Rails 3.1.12 (Medium)

[professor]

1. Find what we need to do to upgrade. Start removing deprecation warnings.

[rofy]

I am using the following guide to know what needs to be done:
http://edgeguides.rubyonrails.org/upgrading_ruby_on_rails.html#upgrading-from-rails-3-0-to-rails-3-1
The main major difference is the asset pipeline.
I have also started upgrading already in my local version and I am trying to fix what's happening in the tests because a lot are failing now...This will take a lot of time...