add initial batch_apex_wait task

[cdcarter]

Critical Changes

Changes

Adds a new task class cumulusci.tasks.batch_apex.BatchApexWait that blocks until a batch job completes.

Usage:
cci task run batch_apex_wait -o class_name BDI_DataImport_Batch.

2017-07-07 13:14:01: Running task: batch_apex_wait
2017-07-07 13:14:02: Options:
2017-07-07 13:14:02:   class_name: BDI_DataImport_BATCH
2017-07-07 13:14:02: Beginning task: BatchApexWait
2017-07-07 13:14:02:
2017-07-07 13:14:08: BDI_DataImport_BATCH: 1 of 20 (0 failures)
2017-07-07 13:14:10: BDI_DataImport_BATCH: 1 of 20 (0 failures)
2017-07-07 13:14:12: Increased polling interval to 3 seconds
[...]
2017-07-07 13:15:54: Increased polling interval to 9 seconds
2017-07-07 13:15:54: BDI_DataImport_BATCH: 20 of 20 (0 failures)
2017-07-07 13:15:54: Job is complete.
2017-07-07 13:15:54: BDI_DataImport_BATCH took 108 seconds to process 20 batches
2017-07-07 13:15:54: Task complete: batch_apex_wait

The task will wait for the most recently submitted batch job for that class_name to complete. This task assumes nobody else is running this class in this org. Be careful in shared orgs.

Issues Closed

[cdcarter]

hey @cpolcyn - I'd love a review when you get a chance.

Additionally, let me know of any opportunities you see for an appropriate unit test? this task is mostly dependent on the poll mechanism but should probably test a success and a failure.

[cpolcyn]

Nice!

[cpolcyn]

Could be removed? I think self._retry() is never called anyway.

[cdcarter]

@jlantz - assigned to you to merge

nvm, chris gave me the 👍