random_color returns an immutable (red, green, blue) tuple of integers from 0 to 255
and random_palette_color picks a named color. Both take an optional random.Random
so that tests can seed them.
Task: MIL-003#1
Task: MIL-003#2
python -m turtle_challenges <challenge> and the turtle-challenges command open a
window, run the named challenge and wait for a click. square and dashed-line are
registered; a missing Tk is reported with a hint instead of a traceback.
Task: MIL-002#6
Tirsvad