Scheduled monthly dependency update for May (#125)

* Update sphinx from 2.0.0 to 2.0.1

* Update isort from 4.3.16 to 4.3.17

* Update pytest from 4.4.0 to 4.4.1

* Update pytest-mock from 1.10.3 to 1.10.4

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Pickle dicts (#123)

* dicts when pickling and better error catching

* returning JobResult and JobDef

* fix linting, tests for unpicklable

* more tests for pickling

* correct docs

Compatible with Python 3.6 (#122)

add run_check (#116)

* add run_check, fix #115

* fix job results

* better exception message

fix Worker redis_settings error

sort all_job_results

update history

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