Run the HTML tests from the CI script

[rocketnia]

This repo predates a lot of what I know now about working with unit tests. A lot of the tests in this repo just print something and assume the person looking at them will know that the output is correct. A lot of the tests run in the browser from .html demo pages, and a couple of those demo pages have actually been showing regressions for some time, probably because I had neglected the .html pages pertaining to features I wasn't actively working on. I fixed up the regressions in the .html pages, and now it would be nice to have npm test run them along with everything else.