Merge tag 'sparks-3.1.3' into develop

3.1.3
Switch to event let in celery configuration if worker concurrency is >= 30.
Switch the worker concurrency options to role, and not hostname.
New dependancies for dev_django_full(), to build new python packages.
Add cython to dev_web().
bump version in __init__.py
Merge branch 'release/3.2'