Expose postal code

[flippinjoe]

First off, the latest version is working great. The only thing I'm missing from it is the postal_code associated with the given ip (if available). I'm not a go person, but it seems like this could be pulled from postal.go in the IncSW area.

[eshepelyuk]

First off, the latest version is working great. The only thing I'm missing from it is the postal_code associated with the given ip (if available). I'm not a go person, but it seems like this could be pulled from postal.go in the IncSW area.

Hello

PRs are welcome since we are not using postal code.