Update geonames.org API hostname

Per http://www.geonames.org/export/JSON-webservices.html#weatherJSON the api endpoint is now on `api.geonames.org`

@dylanegan This is urgent, as it's 40+ degrees and I feel like I should be drinking cider but can't get the validation I need!

cc @quamen
Merge pull request #3 from dgoodlad/patch-1

Update geonames.org API hostname