This release has a breaking change for activities. Instead of $this->model inside activities, it is now $this->storedWorkflow. However, it is recommended to use the new $this->workflowId() helper inside of activities to get the workflow ID instead of accessing the stored workflow directly.
Workflows will now log exceptions to a table. This is added so that the upcoming Waterline UI will be more useful for debugging. The previous migrations should be rolled back before publishing the latest versions. They are not backwards compatible. The migrations and API in general should not be expected to be stable until the first minor release 0.1.0.