Unit testing HTML report JS

[TroyWalshProf]

@jonreding2010 I am not 100% sure we care about adding unit tests to the JS file as outlined in #180.

@dbjorge, mind weighing in here?
My gut is to just exclude the file, but would like a second opinion.

[dbjorge]

I don't see any reason we couldn't/wouldn't want to write unit tests for those. That said, I don't think we need to block "moving them into a separate file" on having unit tests; the js already doesn't have unit tests, moving it to a separate file isn't regressing that. I'd be fine with adding an exclusion for the js file for the purposes of the PR moving it out.