Delayed job integration done

please replace content of boot.rb with

```ruby
# Set up gems listed in the Gemfile.
ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../../Gemfile', __FILE__)
require 'bundler/setup' if File.exist?(ENV['BUNDLE_GEMFILE'])
```

as it is new rails 4 way to boot. Plus, why we need yaml here ?