Vertex now uses true division instead of casting RHS to float

- updated tests

surf/geometry.py

@@ -1,3 +1,4 @@
+from __future__ import division
 import pprint
 
 '''
@@ -66,8 +67,8 @@ class Vertex(object):
 
     def __div__(self, other):
         # same assumption as __mult__
-        other = float(other)
         return Vertex(self.x / other, self.y / other, self.z / other)
+    __truediv__ = __div__
 
     def __neg__(self):
         return Vertex(-self.x, -self.y, -self.z)