code: function(lat, lon, callback) {
  
  			var queryString = "?latitude="+lat+"&longitude="+lon;
  			httpGet(queryString, function(err, results) {
  				callback(err, results);
  			});
  
  		}
docs: callback for getForecastByLatLong
  @callback module:asthma-forecast/client~getForecastByLatLongCallback
  @param {Object} [err] error calling asthma-forecast
  @param {Object} [result] forecast
   
  getForecastByLatLong
  @param {Number} latitude Latitude in decimal degrees
  @param {Number} longitude longitude in decimal degrees
  @param {module:asthma-forecast/client~getForecastByLatLongCallback} [callback] callback