Setup script

@chriddyp, @etpinard, what do you think about throwing warnings here like this?

basically, if you (1) don't have a core package installed (2) if the core package is older than ours and (3) if you have an outdated optional package (think matplotlib)
ugg, had a '/' in there that wasn't supposed to be. this basically says:
(1) with respect to the `plotly` package inside the root directory
(2) include all files matching the patterns:
    a. 'graph_reference/*.json'
    b. '*.json'