Unified unit & end-to-end testing

[flxst]

This PR

• introduces a new script tests/tests.py, which can be used for both unit and end-to-end testing. (6101bb9, 81cacfa, 74045d8, e0d0a42, 563cf27)

  Examples:

  • python tests/tests.py: run CPU tests + single-GPU tests on GPU 0 + multi-GPU tests on GPUs 0/1
  • python tests/tests.py --devices 4,5: same as above but using devices 4/5
  • python tests/tests.py --cpu: run CPU tests
  • python tests/tests.py --single-gpu --devices 3: run CPU tests + single-GPU tests on GPU 3
  • python tests/tests.py --multi-gpu --devices 3,4: run multi-GPU tests on GPUs 3/4

  Note that any GPU device 0-7 can be specified.

• fixes some unit test minor issues (6c4e0f4, 5d2cd14)

• fixes all end-to-end tests (all other commits)

[fromm-m]

We should add the pip packaging to pyproject.toml and run once the git pre-commit hooks so that the actions run through, beside that it can be merged.

[flxst]

We should add the pip packaging to pyproject.toml and run once the git pre-commit hooks so that the actions run through, beside that it can be merged.

Will be done as part of #157.