Merge tag 'sparks-1.20.1' into develop

1.20.1
lower verbosity of manage calls to 1.
Implement the `fast` argument in `collectstatic()`, which will imply removing `STATIC_ROOT` if `False`. This has proven to be necessary in some cases with django-pipeline which sometimes has left partialy-compiled files in the static root, leading to false-negative errors.
bump version in setup.py
Merge branch 'release/1.20.2'