Fix Unit Tests.

Source/MQTTnet/Diagnostics/MqttNetLogMessage.cs

@@ -2,7 +2,7 @@
 
 namespace MQTTnet.Diagnostics
 {
-    public class MqttNetLogMessage
+    public sealed class MqttNetLogMessage
     {
         public string LogId { get; set; }
 

Tests/MQTTnet.Core.Tests/Mockups/TestEnvironment.cs

@@ -46,7 +46,10 @@ namespace MQTTnet.Tests.Mockups
 
             ServerLogger.LogMessagePublished += (s, e) =>
             {
-                Debug.WriteLine(e.LogMessage.ToString());
+                if (Debugger.IsAttached)
+                {
+                    Debug.WriteLine(e.LogMessage.ToString());
+                }
 
                 if (e.LogMessage.Level == MqttNetLogLevel.Error)
                 {
@@ -59,7 +62,10 @@ namespace MQTTnet.Tests.Mockups
 
             ClientLogger.LogMessagePublished += (s, e) =>
             {
-                Debug.WriteLine(e.LogMessage.ToString());
+                if (Debugger.IsAttached)
+                {
+                    Debug.WriteLine(e.LogMessage.ToString());
+                }
 
                 if (e.LogMessage.Level == MqttNetLogLevel.Error)
                 {

Tests/MQTTnet.Core.Tests/Mockups/TestServerWrapper.cs

@@ -135,6 +135,7 @@ namespace MQTTnet.Tests.Mockups
 
         public void Dispose()
         {
+            Implementation.Dispose();
         }
     }
 }

Tests/MQTTnet.Core.Tests/Server_Tests.cs

@@ -15,6 +15,7 @@ using System.Linq;
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
+using MQTTnet.Diagnostics;
 using MQTTnet.Formatter;
 
 namespace MQTTnet.Tests