Update exceptions: remove TaskFailed.details from repr
Update exceptions: use class name in TimeoutError repr
Update exceptions #13: add attribute task to TaskException
Update swf.executor #13: use TaskException.task.name instead of reason attribute
Update task: define repr for ActivityTask ans WorkflowTask
Update setup.py: require simple-workflow>=0.1.40
Merge pull request #14 from botify-labs/fix/task-timeout

Fix/task timeout
Bump version to 0.2.2
Fix swf.executor #15: keep the state of an activity when it is scheduled again
Merge pull request #16 from botify-labs/fix/activity-retry

Fix swf.executor #15: keep the state of an activity when it is scheduled again
Bump version to 0.2.3