Tested on UCBLogo 6.0 with some minor tweaks (for performance and adding
a `timems` function). The tweaks are performed during Docker image
creation (see Dockerfile).
Tests of step 5 are skipped because UCBLogo is too slow.
Interop is available via `(logo-eval "logo code to run")`.
The `examples` directory contains a Mal example of drawing a tree using
turtle graphics.
