Log Message:
py-xdis: updated to 3.8.8

3.8.8:
* Add for 3.6.7 and 3.7.1 magic.
* pytest/test_std.py: Dropped a test
* pytest/test_std.py, xdis/op_imports.py, xdis/std.py: make_std_api
  accepts floating-point version number