API usage:
GET https://abv.peteshadbolt.co.uk/graph -> JSON
POST JSON -> https://abv.peteshadbolt.co.uk/graph
TODO:
GET https://abv.peteshadbolt.co.uk/hadamard/0
GET https://abv.peteshadbolt.co.uk/cz/0/1
GET https://abv.peteshadbolt.co.uk/measure/10/x
etc.
See here for docs.