Log current runner version in terminal (#1441)

src/Runner.Listener/Runner.cs

@@ -312,6 +312,8 @@ namespace GitHub.Runner.Listener
                 }
 
                 HostContext.WritePerfCounter("SessionCreated");
+
+                _term.WriteLine($"Current runner version: '{BuildConstants.RunnerPackage.Version}'");
                 _term.WriteLine($"{DateTime.UtcNow:u}: Listening for Jobs");
 
                 IJobDispatcher jobDispatcher = null;