fix: make write provenance return a graph and add niiri as default namespace
fix: make write provenance return a graph and add niiri as default namespace

grlee77/nipype,wanderine/nipype,fprados/nipype,carolFrohlich/nipype,grlee77/nipype,JohnGriffiths/nipype,Leoniela/nipype,iglpdc/nipype,carlohamalainen/nipype,rameshvs/nipype,wanderine/nipype,arokem/nipype,sgiavasis/nipype,sgiavasis/nipype,JohnGriffiths/nipype,mick-d/nipype,arokem/nipype,gerddie/nipype,iglpdc/nipype,gerddie/nipype,dmordom/nipype,carolFrohlich/nipype,iglpdc/nipype,FCP-INDI/nipype,dmordom/nipype,mick-d/nipype,dgellis90/nipype,mick-d/nipype,wanderine/nipype,pearsonlab/nipype,mick-d/nipype_source,mick-d/nipype_source,grlee77/nipype,blakedewey/nipype,pearsonlab/nipype,arokem/nipype,rameshvs/nipype,blakedewey/nipype,pearsonlab/nipype,arokem/nipype,gerddie/nipype,dgellis90/nipype,pearsonlab/nipype,glatard/nipype,carolFrohlich/nipype,wanderine/nipype,grlee77/nipype,dgellis90/nipype,Leoniela/nipype,glatard/nipype,iglpdc/nipype,fprados/nipype,carlohamalainen/nipype,dmordom/nipype,blakedewey/nipype,gerddie/nipype,rameshvs/nipype,fprados/nipype,JohnGriffiths/nipype,FCP-INDI/nipype,carolFrohlich/nipype,mick-d/nipype,dgellis90/nipype,glatard/nipype,mick-d/nipype_source,FCP-INDI/nipype,rameshvs/nipype,carlohamalainen/nipype,sgiavasis/nipype,JohnGriffiths/nipype,blakedewey/nipype,glatard/nipype,Leoniela/nipype,sgiavasis/nipype,FCP-INDI/nipype