v8.0.0

• [BREAKING] Commands run async functions
• introduces ora as a progress indicator
• exposes a prompt function as a hook into inquirer
• introduces cliui for help output formatting
• fix auto event handler double callback bug
• adds a shortcut colorize function
• Only string values returned from commands are written to stdout
• additional example commands for demonstration
• the interactive flag is excluded from help output if interactive mode is not enabled