Merge branch 'next'

* next:
  Tidy up the Gemfile.
  Use the latest t2flow gem for the tests.
  Add a test for Run#initialized?
  We can't use autogenerated IDs for DJ fixtures.
  Use autogenerated IDs for the Run fixtures.
  Use autogenerated IDs for the RunPort fixtures.
  Use autogenerated IDs for the Workflow fixtures.
  Use an autogenerated ID for the User fixture.
  Allow cancelling a run if its delayed_job fails.
  Add Run#incomplete?
  Add Run#initialized?
  Add Run#pending?
  Test cancelling a Run before it starts running.
  Don't use update_attribute(s) in the models.
  Destroy failed delayed_jobs when destroying Runs.
  Add a test to check if a Run's delayed_job has failed.
  Add rubinius and ruby-head as CI build targets.