This isn't quite the minimal implementation; it does 2 things beyond
the obvious:
1. It anticipates using an Enterprise Policy, either printing the
policies block or temporarily creating a `policies.json` file;
2. It handles redirects to URLs, making it very easy to update
official builds repeatedly.
In the future, it would be nice to build intelligience into this
command so that it's easy to redirect to an entire _directory_ of
updates published from CI -- but that's a problem for another day.
Differential Revision: https://phabricator.services.mozilla.com/D109008
==== mach ==== Mach (German for *do*) is a generic command dispatcher for the command line. To use mach, you install the mach core (a Python package), create an executable *driver* script (named whatever you want), and write mach commands. When the *driver* is executed, mach dispatches to the requested command handler automatically. To learn more, read the docs in ``docs/``.