Update swf.executor: refactor Executor.resume() in several methods
Update history #6: support schedule_failed events
Update swf.executor #6: handle schedule_failed when an activity type does not exist
Update swf.task #6: instanciate a model with .get_or_create()
Update tests.test_dataflow: mock boto.swf.connect_to_region to not require AWS credentials
Update setup.py: require simple-workflow>=0.1.42
Update tests.test_task: remove dangling line
Update tox.ini and .travis.yml: drop builds for python2.6 and 3.3
Merge pull request #17 from botify-labs/update/handle-schedule-activity-not-exist

Update/handle schedule activity not exist