Vector operators

[ZacZhangzhuo]

Describe the bug

for Vector peration *, like:

>>> u = Vector(1.000, 1.000, 0.000)
>>> u * 2
Vector(2.000, 2.000, 0.000)

if we do: Vector * float: It is fine. float * Vector: TypeError: unsupported operand type(s) for *: 'float' and 'Vector'.

Expected behavior I think this could be fixed with minimal effort just for a better user experience. :)