[BioPython] numpy migration for Bio.PDB.Vector

[Christian Meesters]

> Thanks for that.  I did wonder if I should be more explicit - its a
> two step process, file the bug, then add the attachment.  Odd, I
> agree.
Indeed ;-).
> 
> As to the code, I've only skimmed over it.  One thing that caught my
> eye is you are using scipy, which we currently do not want to
> introduce as a Biopython dependency.
Alright, this was only a shortcut to get the determinant. Actually there
is no need to use scipy.
> If you have any views on this migration, please voice them
> (ideally on that thread).
No, nothing to add to things already written.

Christian