0.8.0

new

• new command: list-local-course-exercises
• new command: check-exercise-updates
• new command: update-exercises
• new command: migrate

change

• download-or-update-course-exercises returns a map with downloaded and skipped exercise lists
• ProjectsConfig checks for deleted exercises when loaded
• refactored the rest of all env_logger uses in test modules to simple_logger
• added id field to projects config

etc

• refactored refresh-course progress reporting
• added some docs to refresh-course functions