switch to EUPL license + use pyproject.toml

.gitlab-ci.yml

CHANGES.txt

COPYING

LICENSE

MANIFEST.in

README.md

README.rst

doc/source/conf.py

pyproject.toml

samsam/__info__.py

samsam_env.yml

setup.py

src/samsam/__init__.py

src/samsam/acf.py

src/samsam/logprior.py

tests/test_samsam.py