Do not update platform during startup

sensor.py

@@ -42,11 +42,6 @@ async def async_setup_platform(
     key = config.get(CONF_API_KEY)
 
     alerta = AlertaData(Client(endpoint=url, key=key))
-    await alerta.async_update()
-
-    if not alerta.available:
-        raise PlatformNotReady
-
     dev = [AlertaSensor(alerta, name)]
     async_add_entities(dev, True)
 
@@ -118,9 +113,9 @@ class AlertaData:
         import requests
 
         try:
-            self.status = self.api.mgmt_status()
-            self.alerts = self.api.get_alerts([('status', 'open')])
-            self.keys = self.api.get_keys()
+            self.status = await self.api.mgmt_status()
+            self.alerts = await self.api.get_alerts([('status', 'open')])
+            self.keys = await self.api.get_keys()
             self.available = True
         except requests.exceptions.RequestException:
             _LOGGER.error(