added indication of what Mqtt TargetFramework is used

Frameworks/MQTTnet.NetStandard/TargetFrameworkInfoProvider.cs

@@ -0,0 +1,23 @@
+namespace MQTTnet
+{
+    public static class TargetFrameworkInfoProvider
+    {
+        public static string TargetFramework
+        {
+            get
+            {
+#if NET452
+                return "net452";
+#elif NET461
+                return "net461";
+#elif NETSTANDARD1_3
+                return "netstandard1.3";
+#elif NETSTANDARD2_0
+                return "netstandard2.0";
+#elif WINDOWS_UWP
+                return "uap10.0";
+#endif
+            }
+        }
+    }
+}

Tests/MQTTnet.TestApp.NetCore/MQTTnet.TestApp.NetCore.csproj

@@ -3,7 +3,7 @@
   <PropertyGroup>
     <OutputType>Exe</OutputType>
     <DebugType>Full</DebugType>
-    <TargetFrameworks>netcoreapp2.0;net452</TargetFrameworks>
+    <TargetFrameworks>netcoreapp2.0;net452;net461</TargetFrameworks>
   </PropertyGroup>
 
   <ItemGroup>

Tests/MQTTnet.TestApp.NetCore/Program.cs

@@ -15,7 +15,7 @@ namespace MQTTnet.TestApp.NetCore
     {
         public static void Main()
         {
-            Console.WriteLine("MQTTnet - TestApp.NetFramework");
+            Console.WriteLine($"MQTTnet - TestApp.{TargetFrameworkInfoProvider.TargetFramework}");
             Console.WriteLine("1 = Start client");
             Console.WriteLine("2 = Start server");
             Console.WriteLine("3 = Start performance test");