Added air humidity as property and changed unit to units

Calendar/WeatherForecast.py

@@ -2,6 +2,7 @@ class WeatherForecast (object):
     """Defines a weather forecast, independent of any implementation"""
     def __init__ (self):
         self.air_temperature = None
+        self.air_humidity = None
         self.rain_probability = None
         self.rain_amount = None
         self.sunrise = None
@@ -12,7 +13,7 @@ class WeatherForecast (object):
         self.icon = None
         self.short_description = None
 
-        self.unit = None
+        self.units = None
         self.date = None
         self.place = None
         self.fetch_time = None