Create marvel.py

creates a nodes.json and links.json pages so it can be visualized in a forced graph in
d3.json
https://github.com/mbostock/d3/wiki/Force-Layout
http://nyquist212.wordpress.com/2014/03/11/simple-d3-js-force-layout-example-in-less-than-100-lines-of-code/


hero-network file can be found in http://exposedata.com/marvel/