Add IP address to scan results

[knqyf263]

What did you implement:

Add IP addresses of the scanned server to scan results.

How did you implement it:

Execute ip addr or ifconfig (depends on OS).
Skip loopback address or link-local address, etc. (https://golang.org/pkg/net/#IP.IsGlobalUnicast)

How can we verify it:

Check JSON results after scan.
It will contain IPv4Addrs and IPv6Addrs.

Todos:

• Write tests
• Write documentation
• Check that there aren't other open pull requests for the same issue/feature
• Format your source code by make fmt
• Pass the test by make test
• Provide verification config / commands
• Enable "Allow edits from maintainers" for this PR
• Update the messages below

Is this ready for review?: YES
Is it a breaking change?: NO (Only add columns)

[kotakanbe]

Pretty!