dcmstack create directory if does not exist. pep8 fixes
dcmstack create directory if does not exist. pep8 fixes

FCP-INDI/nipype,mick-d/nipype,mick-d/nipype,wanderine/nipype,wanderine/nipype,pearsonlab/nipype,sgiavasis/nipype,glatard/nipype,dgellis90/nipype,blakedewey/nipype,FCP-INDI/nipype,gerddie/nipype,carolFrohlich/nipype,iglpdc/nipype,blakedewey/nipype,arokem/nipype,dgellis90/nipype,mick-d/nipype,mick-d/nipype,glatard/nipype,sgiavasis/nipype,gerddie/nipype,grlee77/nipype,JohnGriffiths/nipype,glatard/nipype,sgiavasis/nipype,arokem/nipype,JohnGriffiths/nipype,wanderine/nipype,glatard/nipype,gerddie/nipype,arokem/nipype,wanderine/nipype,iglpdc/nipype,FCP-INDI/nipype,blakedewey/nipype,JohnGriffiths/nipype,grlee77/nipype,carolFrohlich/nipype,pearsonlab/nipype,iglpdc/nipype,grlee77/nipype,grlee77/nipype,carolFrohlich/nipype,iglpdc/nipype,blakedewey/nipype,arokem/nipype,dgellis90/nipype,dgellis90/nipype,sgiavasis/nipype,carolFrohlich/nipype,pearsonlab/nipype,JohnGriffiths/nipype,pearsonlab/nipype,gerddie/nipype,FCP-INDI/nipype