Fix cleanenv flag
Fix cleanenv flag

Fix --cleanenv flag (previously mis-spelled as clearenv).
oesteban/preprocessing-workflow,poldracklab/fmriprep,poldracklab/fmriprep,oesteban/fmriprep,oesteban/fmriprep,oesteban/preprocessing-workflow,oesteban/fmriprep,poldracklab/preprocessing-workflow,poldracklab/fmriprep,poldracklab/preprocessing-workflow