Update readme to provide instructions on boot.rb
Merge pull request #19 from mattconnolly/master

Update generators for Rails 3 or 4
Clarify boot.rb adjustment only required if using rspec
Return first default item in a group #13
Merge pull request #20 from 2rk/first-default-child

Return first default item in a group #13
Merge pull request #18 from ridget/feature/update-readme-boot

Update readme to provide instructions on boot.rb