Added missing phpdoc property

[krukru]

IDE did not show support for the getIsoCode method so I found out it's because it is missing from the Result class.

I would also suggest you change the getCity/getLocation/getIsoCode methods to be public, I don't see any value in keeping them hidden.

If you think it's better to keep it protected, I can revert the last commit and just add the new phpdoc property tag.