Javascript Graph Library

Current features:

* Directed Graph

``
import { DirectedGraph } from 'jsgraphlib'

const dg = new DirectedGraph();

const node1 = {name: "node 1"};
const node2 = {name: "node 2"};
const edge12 = {first_node: node1, second_node: node2};

dg.add_node(node1);
dg.add_node(node2);
dg.add_edge(edge12);

console.log(dg.has_node(node1));
console.log(dg.has_node(node2));
console.log(dg.has_edge(edge12));

``