First commit.

Currently just focussing on the logic to create the network
i.e. nodes, edges, layers and grid.

Next: Use NetworkX to view my grid and think about the 'superstructure'
	modified:   README.md
	new file:   network/__init__.py
	new file:   network/create.py
	new file:   network/tests/__init__.py
	new file:   network/tests/test.py