Add another code generator usage
Add numpy array to base unit class
Remove cassandra lines until I can handle arrays
Add randomly generated pos_3d to units
Add ability to calculate distance between units

I'm considering making this an independent function to move away from
the well-worn OO mindset.
Add some cool distance-related python experiments

Doing a few things here:
  -Returning a list from a code generator
  -That list is a list of tuples
  -These tuples were created using the built-in enumerate function
  -When examining this list of tuples later, I retrieve the tuple whose
  second field is the maximum. I do this by defining a key function
  inside the max call, so that it knows which piece to compare. The
  function in this case is a short lambda that retrieves the 2nd value
  in a tuple.