Merge branch 'f-fix-mypy-errors' into 'dev'

.gitlab-ci.yml

CHANGELOG.md

setup.py

src/linkahead/apiutils.py

src/linkahead/common/administration.py

src/linkahead/common/models.py

src/linkahead/common/state.py

src/linkahead/common/versioning.py

src/linkahead/connection/connection.py

src/linkahead/utils/git_utils.py

src/linkahead/utils/plantuml.py

unittests/test_connection.py