TST: Add testing of reduce_rois
TST: Add testing of reduce_rois

FrancoisRheaultUS/dipy,villalonreina/dipy,StongeEtienne/dipy,FrancoisRheaultUS/dipy,demianw/dipy,JohnGriffiths/dipy,nilgoyyou/dipy,demianw/dipy,matthieudumont/dipy,JohnGriffiths/dipy,StongeEtienne/dipy,sinkpoint/dipy,villalonreina/dipy,matthieudumont/dipy,sinkpoint/dipy,nilgoyyou/dipy