With the aim of getting consistency, and removing the need to learn an
additional term, replace uses of uPy/uPython with MPy/MicroPython.
Rule of thumb was to use "MPy" abbreviation where "CPy" is used nearby, but
the full word MicroPython otherwise.
This work was funded through GitHub Sponsors.
Signed-off-by: Angus Gratton <angus@redyak.com.au>
CPython 3.6 has a few changes that, when run on uPy's test suite, give a
different output to CPython 3.5. uPy currently officially supports the
3.4 language definition, but it's useful to be able to run the test suite
with 3.4/3.5/3.6 versions of CPython. This patch makes such changes to
support 3.6.
