* always run with a clean cache
* in the future we should structure the tests so they run twice, once with a clean cache and then again with a populated one, but for now a clean cache should catch more bugs
* stop requiring a file cache path for tests; just use
* fix exit codes to match documentation at the top of the file: 1 is a test failure, 2 is bad args
Squash-merge of my #198.
We are going to need some nginx-specific system tests, and this seemed like a
good place to start. This adds two tests, as well as some infrastructure. With
Squash-merge of my #194 and #195