Mid-update progress save
Mid-update progress save

Updating Okabe code to work with new StreetNet class and associated
methods. So far have only changed some stuff in the __main__ section,
but full treatment to come (committing as want to change computers).
One other change - changed some terminology in the Edge class, just for
consistency and because I was finding it hard to keep track. Shouldn’t
break anything.

gaberosser/geo-network