Updated Haml
Updated development dependencies
Updated Test/Development Gems
Updated Database Cleaner

The mentioned ticket is closed for some time now
Updated Devise & Omni Auth for Twitter
Updated RedCarpet
Updated CarrierWave & MiniMagick
Set SimpleForm to the released version

3.0.0 is now long released. We don't need the Github Version any
longer.
Updated Chartkick
Updated: Rake, Uglifier, ExecJS