v4.0

This version separates the processing of each file type (*.acq, *.dcm or *.puls/*.resp) as a different sub-package.

People will be able to pip install a single sub-package (e.g.: pip install bidsphysio.acq2bids) and only the needed dependencies will be installed.

People can also install the full package with pip install bidsphysio.

Command-line usage stays the same; Python sub-package imports change slightly.