When traversing upwards, it's possible `/` maps to a different drive than where the CWD is (usually, `C:\\`).
Closes #100, which has more details. Bug introduced in 897db69.
It seems the latest version works again (as expected).
Green lighted the tests, fixed any lint errors, and refactored _searchFile based on the FIX ME note.
Start with cwd, traverse up filesystem and fall back on HOME, if available.