updated qball.py
updated qball.py

nilgoyyou/dipy,StongeEtienne/dipy,FrancoisRheaultUS/dipy,rfdougherty/dipy,jyeatman/dipy,JohnGriffiths/dipy,maurozucchelli/dipy,samuelstjean/dipy,oesteban/dipy,JohnGriffiths/dipy,StongeEtienne/dipy,villalonreina/dipy,demianw/dipy,demianw/dipy,villalonreina/dipy,mdesco/dipy,samuelstjean/dipy,Messaoud-Boudjada/dipy,sinkpoint/dipy,beni55/dipy,sinkpoint/dipy,FrancoisRheaultUS/dipy,beni55/dipy,mdesco/dipy,rfdougherty/dipy,samuelstjean/dipy,nilgoyyou/dipy,Messaoud-Boudjada/dipy,maurozucchelli/dipy,maurozucchelli/dipy,matthieudumont/dipy,jyeatman/dipy,oesteban/dipy,matthieudumont/dipy