Add more tests

@meshy I use it every time I debug one of those things.  They're big and hard to read, but being able to see the HTML you're scraping makes a massive difference in trying to figure out why your test is wrong or what's broken in your code.  I'd like there to be a way of displaying them as something other than byte strings, so you get line breaks and indentation and stuff, but I had a quick go and couldn't find anything.