Hostname should be a required parameter

[ceremcem]

If there are many controllers/machines in the field, they share the same username (NODE_USER) and they either have the same password or are configured to let the same RSA key for passwordless login (where ./make-target-settings.sh performs); then the following scenario may pose from trivial to catastrophic consequences:

If there are more than one controller in the field and their IP address is assigned by the DHCP server, when DHCP server accidentally switches their IP addresses, developer may perfectly connect to the wrong controller (Linux machine) with the right IP address.

Proposal

A NODE_HOSTNAME parameter should be required so that this name can be used to check if the developer is connected the right target or not.