Return an error code if the program is called with no arguments.
Return an error code if the program is called with no arguments.

If we want to provide the help screen without an error code there
should be a --help option.  An empty command line could pretty easily
by a typo or error in the program that is starting this program, so
that should result in an error code.

DavidEGrayson/update-nix-fetchgit