Write a minimal test for slicing the simplest wav file

- [ ] Familiarize yourself with the very basics of [pytest](https://docs.pytest.org/)
- [ ] Create the file `tests/test_slicer.py`
- [ ] Define a test in test_slicer.py called `test_audio_slicing`
- [ ] In your test, create a simple wav file per https://stackoverflow.com/a/57192182/271697
- [ ] In your test, call audio_slicing() with your wav file and verify that the slices are created

If you have more experience with pytest and want to use fixtures, etc. you can, or you can just write the simplest possible test per above and we can iterate later.