Upgrade uglifier gem to v2.5.1
Upgrade roar-rails gem to v0.1.6 along with its dependencies (representable, nokogiri, etc.)
Upgrade paper_trail gem to v3.0.2
Upgrade jquery-rails gem to v3.1.1
Upgrade font-awesome-rails gem to v4.1.0.0
Replace non-breaking spaces with normal spaces in Gemfile
Upgrade capybara gem to v2.3.0
Upgrade database_cleaner gem to v1.3.0
Upgrade guard-rspec gem to v4.2.10 + dependencies

Removed 'spring' and 'binstubs' options which are deprecated. In the
case of spring, it has been transparently integrated into rails and I
belive it's not necessary anymore...