I don't really like this because the tests will silently not be compiled
if you haven't set the environment variables, so you'd only notice you
weren't running the tests if you looked for those tests' output lines
and saw they weren't there.
Ideally, I'd like to print a warning, but this isn't possible because:
- Anything printed in tests doesn't show up by default
- Cargo's build scripts can't tell whether you're building as a
dependency or building for that crate's tests, so the warning would show
up even if you just depended on delorean_object_store
(https://github.com/rust-lang/cargo/issues/2549)
Jake Goulding
Carol (Nichols || Goulding)