Cargo's subcommand emacs-module

[ubolonton]

Writing a module still involves many ad-hoc scripts (test.sh, load.sh) and manual steps (e.g. renaming files).

There should be a cargo's subcommand that supports at least the following:

• new: Create a new module.
• test: Run integration (ert) tests.
• load: Load the module into a running Emacs daemon. Reload if it's already loaded.
• package: Create a correctly-named file that can be dropped into a directory in load-path.