More informative validation errors & explicitly setting a priority_rank (which is also set in the schema)
Updating cloud-crowd's sinatra dependency and requiring yaml for ruby 1.9
Update tests to work with newer versions of gems

Still requires Active Record 2.3
add a clear database helper; auto-migrate test db
Test priority rank for jobs and work_units
Use 'Priority Rank', 'Updated At' for ordering

Use validates_numericality_of instead of custom validator and incldue
priority_rank in json reprentation
Test that submitted jobs respect priority rank
Use Bundler and Guard for convenience

executing 'bundle exec guard' will start a watcher and auto-run tests
when a file is saved.  Pass/Fail results are sent to growl