Merge branch 'dev' into f-improve-diff-descriptions

CHANGELOG.md

src/doc/tutorials/complex_data_models.rst

src/linkahead/__init__.py

src/linkahead/apiutils.py

src/linkahead/common/models.py

src/linkahead/utils/linkahead_admin.py

unittests/test_apiutils.py

unittests/test_entity.py