Update non-web related dependencies to their latest version were
possible. It appears yargs has changed its parsing of command line
options to no longer remove a layer of quotes.
The LTS releases for v12 and v14 are already end of life and the v16 is
end of life in under two months from now on. Bump supported version up
to v18 as it does not make sense to continue to support EOL releases.
Even if we wanted to keep supporting them, our dependencies will not.
Note that Node.js v18 is currently not avaliable via the NodeSource PPA
on Ubuntu 19.10 and below or Debian 9 and below.
The role of a slave as a host for Factorio servers is not well reflected
in its name and has caused confusion among users. Rename slave to host
to better reflect its role as a host of Factorio servers.
Hornwitser