"Snapshot tests" of analysis results

[mattwigway]

It would be good to make integration tests that snapshot analysis results the same way we snapshot JS components, with files that are autogenerated and can be easily updated (rather than constants hardwired in code). I hadn't initially done this due to the randomness in the results, but it occurs to me that (a) when not using frequencies, there is no randomness; (b) we might be able to seed the Mersenne Twister so that randomness was deterministic (this may not work, though, because the order we pull numbers out of the RNG to make random timetables may depend on the iteration order of a hashmap somewhere, but I don't think so); (c) even if we can't isolate the randomness, we built a thing (the bootstrap code) to determine if changes are statistically significant.

[ansoncfit]

Closing in favor of #714