Generating thrift files

The files in lib/thrift are generated by thrift. Should Twofishes change the API definition in geocoder.thrift, the files bundled with the gem need to be regenerated.

$ thrift --gen rb -o /path/to/lib /path/to/twofishes-master/interface/src/main/thrift/geocoder.thrift

Then rename gen-rb folder to thrift folder and remove require statements from files.