fix: designe HealthAsync() as obsolete in interface (#360)

Author: knollsen

Diff for: CHANGELOG.md

@@ -5,6 +5,7 @@
 
 ### Bug Fixes
 1. [#353](https://github.com/influxdata/influxdb-client-csharp/pull/353): Support for `double` types in LINQ expression [LINQ]
+2. [#360](https://github.com/influxdata/influxdb-client-csharp/pull/360): Designated `HealthAsync` as obsolete in `IInfluxDBClient`
 
 ### Dependencies
 Update dependencies:

Diff for: Client/InfluxDBClient.cs

@@ -181,6 +181,7 @@ public interface IInfluxDBClient : IDisposable
         /// Get the health of an instance.
         /// </summary>
         /// <returns>health of an instance</returns>
+        [Obsolete("This method is obsolete. Call 'PingAsync()' instead.", false)]
         Task<HealthCheck> HealthAsync();
 
         /// <summary>