Fix remaining tests.

[jamestalmage]

There are a few tests I think I did a poor adapting to fit our new testing strategy. @novemberborn had an alternate test strategy PR that we didn't go with, but I think it did adapt a few of the tests better.

We need to make sure we identify those and merge them in.

See:

• wip! use tap.spawn() for each test #85
• Caching #101 (comment)