BF - fixed dtype issue in _switch_vertex
BF - fixed dtype issue in _switch_vertex

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