.py files are valid source files and shouldn't be ignored. This line was
from the early days when .py files in the unix directory were used for
testing.
Signed-off-by: Damien George <damien@micropython.org>
This is to keep the top-level directory clean, to make it clear what is
core and what is a port, and to allow the repository to grow with new ports
in a sustainable way.
