Generate UpSet visualizations for set intersections

[rdocking]

From either:

• The intersection of the annotation sources
• The intersection of the observation data

... generate an UpSet-style plot, showing the intersections between different sources.

[eacton]

@rdocking I put the 'fake' upset plots under the analysis folder. I will make an executable script once we have the 'real' output. If it is after the hackathon, just tag me and I'll do it.