Merge branch 'release/1.8.0'

pybis/src/python/CHANGELOG.md

pybis/src/python/LICENSE

pybis/src/python/README.md

pybis/src/python/README.rst

pybis/src/python/notebooks/openBIS+masterdata.ipynb

pybis/src/python/pybis/__init__.py

pybis/src/python/pybis/attribute.py

pybis/src/python/pybis/dataset.py

pybis/src/python/pybis/definitions.py

pybis/src/python/pybis/pybis.py

pybis/src/python/pybis/things.py

pybis/src/python/pybis/utils.py

pybis/src/python/setup.py

pybis/src/python/tests/conftest.py

pybis/src/python/tests/test_dataset.py