Add 'forecast' ability to yr weather sensor (#8650)

* Add forecast option to YR sensor

* Fix some style issues

* Fix linting

tests/components/sensor/test_yr.py

@@ -69,3 +69,45 @@ def test_custom_setup(hass, aioclient_mock):
     state = hass.states.get('sensor.yr_wind_speed')
     assert state.attributes.get('unit_of_measurement') == 'm/s'
     assert state.state == '3.5'
+
+
+@asyncio.coroutine
+def test_forecast_setup(hass, aioclient_mock):
+    """Test a custom setup with 24h forecast."""
+    aioclient_mock.get('https://aa015h6buqvih86i1.api.met.no/'
+                       'weatherapi/locationforecast/1.9/',
+                       text=load_fixture('yr.no.json'))
+
+    config = {'platform': 'yr',
+              'elevation': 0,
+              'forecast': 24,
+              'monitored_conditions': [
+                  'pressure',
+                  'windDirection',
+                  'humidity',
+                  'fog',
+                  'windSpeed']}
+    hass.allow_pool = True
+    with patch('homeassistant.components.sensor.yr.dt_util.utcnow',
+               return_value=NOW), assert_setup_component(1):
+        yield from async_setup_component(hass, 'sensor', {'sensor': config})
+
+    state = hass.states.get('sensor.yr_pressure')
+    assert state.attributes.get('unit_of_measurement') == 'hPa'
+    assert state.state == '1008.3'
+
+    state = hass.states.get('sensor.yr_wind_direction')
+    assert state.attributes.get('unit_of_measurement') == '°'
+    assert state.state == '148.9'
+
+    state = hass.states.get('sensor.yr_humidity')
+    assert state.attributes.get('unit_of_measurement') == '%'
+    assert state.state == '77.4'
+
+    state = hass.states.get('sensor.yr_fog')
+    assert state.attributes.get('unit_of_measurement') == '%'
+    assert state.state == '0.0'
+
+    state = hass.states.get('sensor.yr_wind_speed')
+    assert state.attributes.get('unit_of_measurement') == 'm/s'
+    assert state.state == '3.6'