This reduces the confusion with the nixos/modules/deployment.nix module,
and should make it clearer that it can contain any configuration that
applies to all hosts on the grid.

Use convention to find the file from which the public key can be read.

update the localdev grid's secrets and other configuration to reflect this

testing and production are broken by this commit since they have not been
updated similarly

update the localdev grid's secrets and other configuration to reflect this

testing and production are broken by this commit since they have not been
updated similarly

Also add my key to local secrets for the moment because otherwise localdev
grid cannot build itself :/

It is no longer required to add IP addresses to the Vagrant-generated ssh
configuration because the Vagrant-configured hostnames now match up with the
names morph will try to use to connect to the VMs.

Just require hostName and domain instead of an extra publicIPv4 option.  Leave
behind a similar option, `publicAddress`, just in case it needs to be
overridden at some point, but stop supplying a value for it anywhere.