`test_group_in_chain_json` is hanging:

```
This test protects against an issue with nested chains and groups when encoding with json. ...
 -------------- celery@euclid.r.igoro.us v3.1.14 (Cipater)
---- **** -----
--- * ***  * -- Linux-3.10.25-aufs-2014022401-aufs-x86_64-AMD_Phenom-tm-_II_X2_555_Processor-with-gentoo-2.2
-- * - **** ---
- ** ---------- [config]
- ** ---------- .> app:         relengapi.app:0x7f8850501d90
- ** ---------- .> transport:   sqla+sqlite:////home/dustin/code/relengapi/t/relengapi/relengapi/tests/test_temp/celery.db
- ** ---------- .> results:     db+sqlite:////home/dustin/code/relengapi/t/relengapi/relengapi/tests/test_temp/celery.db
- *** --- * --- .> concurrency: 2 (solo)
-- ******* ----
--- ***** ----- [queues]
 -------------- .> celery           exchange=celery(direct) key=celery


[2014-10-16 09:13:09,846: WARNING/MainProcess] celery@euclid.r.igoro.us ready.
[2014-10-16 09:13:10,164: WARNING/MainProcess] /home/dustin/code/relengapi/t/relengapi/sandbox/lib/python2.7/site-packages/celery/app/trace.py:364: RuntimeWarning: Exception raised outside body: AttributeError("'dict' object has no attribute 'type'",):
Traceback (most recent call last):
  File "/home/dustin/code/relengapi/t/relengapi/sandbox/lib/python2.7/site-packages/celery/app/trace.py", line 280, in trace_task
    signature(callbacks[0], app=app).delay(retval)
  File "/home/dustin/code/relengapi/t/relengapi/sandbox/lib/python2.7/site-packages/celery/canvas.py", line 168, in delay
    return self.apply_async(partial_args, partial_kwargs)
  File "/home/dustin/code/relengapi/t/relengapi/sandbox/lib/python2.7/site-packages/celery/canvas.py", line 487, in apply_async
    type = self.type
  File "/home/dustin/code/relengapi/t/relengapi/sandbox/lib/python2.7/site-packages/celery/canvas.py", line 550, in type
    app = self._app if self._app else self.tasks[0].type.app
AttributeError: 'dict' object has no attribute 'type'

  exc, exc_info.traceback)))
[2014-10-16 09:13:10,165: CRITICAL/MainProcess] Task relengapi.tests.test_celery.test_task_json[2485aad4-2c80-489c-a9d0-a0ca4f97693f] INTERNAL ERROR: AttributeError("'dict' object has no attribute 'type'",)
Traceback (most recent call last):
  File "/home/dustin/code/relengapi/t/relengapi/sandbox/lib/python2.7/site-packages/celery/app/trace.py", line 280, in trace_task
    signature(callbacks[0], app=app).delay(retval)
  File "/home/dustin/code/relengapi/t/relengapi/sandbox/lib/python2.7/site-packages/celery/canvas.py", line 168, in delay
    return self.apply_async(partial_args, partial_kwargs)
  File "/home/dustin/code/relengapi/t/relengapi/sandbox/lib/python2.7/site-packages/celery/canvas.py", line 487, in apply_async
    type = self.type
  File "/home/dustin/code/relengapi/t/relengapi/sandbox/lib/python2.7/site-packages/celery/canvas.py", line 550, in type
    app = self._app if self._app else self.tasks[0].type.app
AttributeError: 'dict' object has no attribute 'type'
```