fix: address pep8 errors, improve check on containerized exec.
fix: address pep8 errors, improve check on containerized exec.

poldracklab/preprocessing-workflow,oesteban/fmriprep,oesteban/fmriprep,poldracklab/fmriprep,poldracklab/preprocessing-workflow,poldracklab/fmriprep,oesteban/fmriprep,poldracklab/fmriprep