Actually call the scheduler on relevant changes
Require celery with redis
Another attempt at including celery+redis
Make travis start a redis server
Remove pymsql on Python 3.3 from allowed failures

SQLAlchemy is at 0.9.4 now, so these should work again
Retry failed tasks

This does not yet make sure tasks are not retried on the same agent they
just failed on.
Bugfix when checking for dependencies.

State can be NULL, and in some SQL implementations not checking for that
explicitly can lead to unexpected results
Merge pull request #130 from guidow/dependency_bugfix

Bugfix when checking for dependencies.
Merge pull request #128 from guidow/retry_failed_tasks

Retry failed tasks
Merge pull request #125 from guidow/reduce_allowed_failures

Remove pymsql on Python 3.3 from allowed failures (follow up to #86)
manually merging guidow:call_scheduler_on_changes into master (closes #124)