Weather Application

This is the new application that will be used to serve `ajax` weather requests.

There are two endpoints that can be called;
 - `/weather/city.json` - This is for when the caller does not know where they are located. It tries to resolve the city that will be received from fastly and if this cannot be resolved from `AccuWeather`, it falls back to the hard-coded `CityID` for the `Edition` of the `request`; this will always be at least `Uk`.
 - `/weather/city/london.json` - This is for when you know where you are.

This may change to having city IDs as another endpoint.

@uplne @robertberry @gklopper 
What does this actually return? It looks like it returns a CityId, in which case I'm not sure if the method name is very descriptive