Changed the MesosStatusUpdateEvent taskStatus parameter to a String instead of an Int. Thus, this event is now created with the TaskStatus.TaskState.name instead of the enum's ID. This provides a more meaningful task state such as TASK_STAGING, TASK_STARTING, TASK_RUNNING, TASK_FINISHED, TASK_FAILED, TASK_KILLED and TASK_LOST.
Merge pull request #248 from Shopify/task-status-as-string

Proposal: Change the MesosStatusUpdateEvent taskStatus parameter to a String