Tests - documentation and setup

[rlskoeser]

• Tests were not documented anywhere in the repo that I could find; consider either adding a brief section to the main readme, or another document somewhere (readme in tests directory, or a testing.md or some such) that is referenced and linked from the main document
• Provide instructions about setting up the tests, installing dependencies, how to run the tests
• Tests seem to expect particular data to be loaded; the approach I've generally seen for automated tests is to load known fixture data to test against. If this is not feasible, then at the very least the documentation needs to provide information about what data the tests expect to be loaded.
• Add error reporting that would provide information about what happens when a test failed - when I tried running the tests they failed for me, but I couldn't tell where exactly it was going wrong
• The exist base url & collection should be configurable, not hard-coded; include any configuration or expected environment variables in the documentation