How to build a CLI gem

1. Plan your gem, imagine your interface
2. Start with the project structure - google
3. Start with the entry point - the file run
4. Force that to build the CLI interface
5. Stub out the interface
6. Start making things real
7. Discover objects.
8. Program

- Greet user
- Present user with menu and asks for user input to choose either a list from the menu or exit
- If list, present with list and an option to choose an item from the list
- If exit, give a farewell message and quit program