Merge branch 'master' into 'pylint_and_other_fixes'

# Conflicts:
#   README.md
#   connect_4/artificial_intelligence.py
#   connect_4/game_elements.py
#   connect_4/main.py
#   connect_4/main_menu.py
#   tests/e2e/everything.feature
#   tests/e2e/steps/steps.py
#   tests/unit/test_artificial_intelligence.py
#   tests/unit/test_game_elements.py