add --output / -o option to override the default .socket.facts.json output file for socket scan reach

[mtorp]

Adds the option --output or -o to socket scan reach to allow you write the resulting report to a custom file

# writes the results to .socket.facts.json
socket scan reach

# writes the results to ~/my-reports/foo.json
socket scan reach -o ~/my-reports/foo.json

[jdalton]

Merging in manually.