Upgrade Rails to 4.0.9

Upgrades sass-rails to 4.0.2 so we're compatible.
Allow DFID finder to be crawled by robots
Merge pull request #60 from alphagov/rails-409

Upgrade Rails to 4.0.9
Merge pull request #61 from alphagov/allow-dfid-finder-robots

Allow DFID finder to be crawled by robots