unit test failing on travis ci

[tdiethe]

Logging output:

root: INFO: New workflow created with id test_new_api_overlapping_plates
root: INFO: Added workflow test_new_api_overlapping_plates to workflow manager
root: INFO: Added node with id ticker containing 1 streams
root: INFO: Added node with id rr1 containing 4 streams
root: INFO: Added node with id rr2 containing 4 streams
root: INFO: Added node with id rp containing 16 streams
root: INFO: Added node with id rpc containing 16 streams
root: INFO: Added factor with tool Clock(first=datetime.datetime(1, 1, 1, 0, 0, 0, 0, tzinfo=UTC, stride=1.0) 
root: INFO: Added factor with tool Random(seed=1) 
root: INFO: Added factor with tool Random(seed=2) 
root: INFO: Added factor with tool Product() 
root: INFO: Added factor with tool Dummy() 
root: INFO: Dummy with sink node rpc running from 2016-04-28 20:00:00+00:00 to 2016-04-28 20:01:00+00:00
root: INFO: Product with sink node rp running from 2016-04-28 20:00:00+00:00 to 2016-04-28 20:01:00+00:00
--------------------- >> end captured logging << ---------------------
mongoengine/base/fields.py   RuntimeError: dictionary changed size during iteration

[tdiethe]

Test is passing, but we still get these dictionary changed errors:

plugins_data_generators_tools_gammavariate_2017_06_20_v1_0_0.py   RuntimeError: dictionary changed size during iteration
mongoengine/errors.py   RuntimeError: dictionary changed size during iteration
mongoengine/fields.py   RuntimeError: dictionary changed size during iteration
hmac.py   RuntimeError: dictionary changed size during iteration
numbers.py   RuntimeError: dictionary changed size during iteration

[tdiethe]

Still getting this error - now in a different location!

hyperstream/time_interval.py   RuntimeError: dictionary changed size during iteration

See this build