If a command does not exist, nerd should say so

[LilliJane]

If a user types nerd project sets test it will return the help message and Not enough arguments.

[advdv]

This behaviour is seemingly hardcoded in the CLI library so seems hard to change: https://github.com/mitchellh/cli/blob/33edc47170b5df54d2588696d590c5e20ee583fe/cli.go#L232 I can add a line in the main.go that checks for 127 but that is brittle and doesn't work on subcommands. I'm removing this from this milestone.