There are warnings on Github workflows about the need to update actions
'checkout' and 'setup-python' due to the use of Node.js versions that
are too old.
This patch updates the use of actions/checkout from v2 to v3.1.0, and
setup-python from v2 to v4.3.0.
The main REAADME has been fixed to contain information about the
automount key and map modules, the reference to the hbacsvcgroup README
has been fixed and a new test has been added as a github workflow.