Log Message:
py-astroid: updated to 2.5.6

What's New in astroid 2.5.6?
============================
Release Date: 2021-04-25

* Fix retro-compatibility issues with old version of pylint

What's New in astroid 2.5.5?
============================
Release Date: 2021-04-24

* Fixes the discord link in the project urls of the package.

What's New in astroid 2.5.4?
============================
Release Date: 2021-04-24

* The packaging is now done via setuptools exclusively. ``doc``, ``tests``, and \ 
``Changelog`` are
  not packaged anymore - reducing the size of the package greatly.

* Debian packaging is now  (officially) done in \ 
https://salsa.debian.org/python-team/packages/astroid.

* ``__pkginfo__`` now  only contain ``__version__`` (also accessible with \ 
``astroid.__version__``),
  other meta-information are still accessible with ``import \ 
importlib;metadata.metadata('astroid')``.

* Added inference tip for ``typing.Tuple`` alias

* Fix crash when evaluating ``typing.NamedTuple``

* COPYING was removed in favor of COPYING.LESSER and the latter was renamed to \ 
LICENSE to make more apparent
  that the code is licensed under LGPLv2 or later.

* Moved from appveyor and travis to Github Actions for continuous integration.