Remove 'volume' from return dict (#15842)

https://github.com/home-assistant/home-assistant/issues/15271

intraday results do not return the volume. See https://www.alphavantage.co/documentation/#intraday

homeassistant/components/sensor/alpha_vantage.py

@@ -22,7 +22,6 @@ _LOGGER = logging.getLogger(__name__)
 ATTR_CLOSE = 'close'
 ATTR_HIGH = 'high'
 ATTR_LOW = 'low'
-ATTR_VOLUME = 'volume'
 
 CONF_ATTRIBUTION = "Stock market information provided by Alpha Vantage"
 CONF_FOREIGN_EXCHANGE = 'foreign_exchange'
@@ -148,7 +147,6 @@ class AlphaVantageSensor(Entity):
                 ATTR_CLOSE: self.values['4. close'],
                 ATTR_HIGH: self.values['2. high'],
                 ATTR_LOW: self.values['3. low'],
-                ATTR_VOLUME: self.values['5. volume'],
             }
 
     @property