Fixed a bug in tf.py where a call to Quat.vector() would throw an err…

…or instead of returning the imaginary vector portion of a quaternion.

python/amino/tf.py

@@ -515,7 +515,7 @@ def to_eulerzyx(self):
 
     def vector(self):
         """Returns the vector (xyz) part"""
-        return Vec3(self.x, self.y, self.z)
+        return Vec3([self.x, self.y, self.z])
 
     def scalar(self):
         """Returns the scalar (w) part"""