Assumes nodes to be array rather than object

[Ansoulom]

I have found that this tool is inconsistent with the spec at https://github.com/jsongraph/json-graph-specification. The specification says that "nodes" should be an object, but this tool assumes that it is an array. Perhaps this tool uses V1 of the spec rather than the more recent V2?

[wshayes]

This tool hasn't been updated to V2 of the JGF specification. Happy to accept pull requests :)

[osequi]

This is the V1 spec format which works well: https://jsongraphformat.info/v1.0/json-graph-schema.json