First set of correction in introduction to basic tracking tutorial
First set of correction in introduction to basic tracking tutorial

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