Sometimes we mistype commands but Gluestick was just silently doing nothing. Users should be informed that they attempted to perform an unknown command and then shown the help to provide them with known commands.

I went to create a container, accidentally did gluestick generate component something and realized it would be nice to have a destroy method like Rails. I more or less copied what is in src/commands/generate.js but modified it as needed.

Something to consider:
Steps 1 - 4 in destroy and generate are the same aside from the messages they log. Does that warrant possible extraction?