Backwards-incompatible Changes:

    * Remove #requeue from all backends. It was not used internally.
    * Move implicit Rails dependency to it's own Gem, which you must declare now in your Gemfile.

        gem 'qu-rails'

  Enhancements

    * qu-mongo: Add mongolab environment variable for automatic configuration on Heroku.

  Bug Fixes:

    * Fixing Immediate backend to satisfy the backend interface