Add CI

[trin94]

Hey,

I've added CI jobs for the project. They run on Windows and Ubuntu 22.04 using Python 3.8 - Python 3.10 respectively. On Ubuntu, we install libmpv using the package manager, on Windows we get a build from sourceforge :sweat_smile:

Two major things worth mentioning:

• I could not run tests on Python 3.7:

  ==================================== ERRORS ====================================
  ______________________ ERROR collecting tests/test_mpv.py ______________________
  ImportError while importing test module '/home/runner/work/python-mpv/python-mpv/tests/test_mpv.py'.
  Hint: make sure your test modules/packages have valid Python names.
  Traceback:
  /opt/hostedtoolcache/Python/3.7.13/x64/lib/python3.7/importlib/__init__.py:127: in import_module
  return _bootstrap._gcd_import(name[level:], package, level)
  tests/test_mpv.py:30: in <module>
  import mpv
  mpv.py:26: in <module>
  from concurrent.futures import Future, InvalidStateError
  E   ImportError: cannot import name 'InvalidStateError' from 'concurrent.futures' (/opt/hostedtoolcache/Python/3.7.13/x64/lib/python3.7/concurrent/futures/__init__.py)
  =========================== short test summary info ============================
  ERROR tests/test_mpv.py
  !!!!!!!!!!!!!!!!!!!! Interrupted: 1 error during collection !!!!!!!!!!!!!!!!!!!!
  =============================== 1 error in 0.38s ===============================

• There is one test that I could not get to work on Ubuntu: test_wait_for_property_event_overflow. We're now skipping this test on Ubuntu but run it on Windows.

There are quite a few commits. I deceived to keep them so that you can follow my thought process. If you decide to merge this PR, feel free to squash them :+1:

Edit: Link to the actions in action: https://github.com/trin94/python-mpv/actions

[jaseg]

Looks good to me. Thanks for going to the effort!

The test_wait_for_property_event_overflow test AFAIR depends on some libmpv build-time constant and is timing-sensitive. Since it is only checking that a safeguard works anyway, and since actually triggering this overflow condition is fairly difficult in practice, I think it's fine if that does not run on all platforms.

I wasn't aware of the python 3.7 issue. I obviously broke that adding the new future-based async features. I'm going to look into that, but I can imagine simply dropping 3.7 support since 3.7 only has a year left until its upstream EOL anyway, and even debian stable is on 3.9 by now.