Create graphs of #1919 torperfs

It would be great if we had some sort of output of the 15 torperf runs that are running somewhere. Right now, afaik, all that data will just go into a hole until someone decides to dig it up.

In my ideal world, we'd have the ability to see all the graphs on https://metrics.torproject.org/performance.html for each one of these runs, right there live on the website.

If this is too much work to be done in a reasonable amount of time, I'd settle having just the timing graphs for each of the 15 runs in a directory I can access somewhere.