Create cli/main.py with the following commands:
- add <text> [--link url] [--due date] - Add a new bounty
- list - List all bounties in room
- my - List tracked bounties for user
- update <id> [text] [--link url] [--due date] [--clear-link] [--clear-due]
- delete <id> - Delete a bounty
- track <id> - Track a bounty
- untrack <id> - Untrack a bounty
Context flags:
- --group-id <id> - Group context
- --user-id <id> - User context
Requires either --group-id or --user-id for all commands.
Fixes#11
