Upgrade ruby from 2.1.2 to latest version 2.1.5. Keep .ruby-gemset out of repo.
Delete mailcatcher from Gemfile as per github.com/sj26/mailcatcher/blob/master/README.md#bundler. Not using it anyway.
Update sdoc gem from 0.3.20 to 0.4.1.
Update gems rspec & rspec-rails.
Update gem draper.
Update coffee-rails gem & dependencies.