added benchmark option to compare netfx and core runtime

Tests/MQTTnet.Benchmarks/Configurations/AllowNonOptimized.cs

@@ -0,0 +1,20 @@
+using System.Linq;
+using BenchmarkDotNet.Configs;
+using BenchmarkDotNet.Jobs;
+using BenchmarkDotNet.Validators;
+
+namespace MQTTnet.Benchmarks.Configurations
+{
+    /// <summary>
+    /// this options may be used to run benchmarks in debugmode and attach a performance profiler
+    /// https://benchmarkdotnet.org/Configs/Configs.htm
+    /// </summary>
+    public class AllowNonOptimized : BaseConfig
+    {
+        public AllowNonOptimized()
+        {
+            Add(JitOptimizationsValidator.DontFailOnError); // ALLOW NON-OPTIMIZED DLLS
+            Add(Job.InProcess);
+        }
+    }
+}