research(client): decide on graph data viz library

[CoreyCole]

We need to find a graph visualization library that we think will fit our requirements for both the minimum viable demo and later iterations where we'd like to show more fine-grained animations describing the covariate discovery algorithm.

[CoreyCole]

@pzli3 found https://github.com/dagrejs/dagre-d3/wiki

It hasn't been developed on in a few years, but people say it is very useful. It won't work if we want to easily do animations for v2. When we want to do animations we will probably need to look into a different library.