Should np.sh default to using -s and -i flags?

[cpswan]

Is your feature request related to a problem? Please describe.

An install of sshnp into a fresh environment is likely to fail unless keys have already been put in place

Describe the solution you'd like

Use the -s and -i flags in np.sh to ensure that keys on the client machine are transported to the target device.

Describe alternatives you've considered

These could be the default for sshnp itself, but I'm not persuaded that it's a secure default.

Additional context

Do we expect our users to know their way around ssh key management?