Migrate to .NET Standard 2.0

Client/Client.csproj

@@ -0,0 +1,12 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="CoAP" Version="1.1.0" />
+  </ItemGroup>
+
+</Project>

Client/Program.cs

@@ -0,0 +1,20 @@
+using System;
+
+namespace Client
+{
+    using System.Threading.Tasks;
+    using CoAP;
+
+    class Program
+    {
+        static async Task Main(string[] args)
+        {
+            var client = new CoapClient(new Uri("coap://127.0.0.1:5683/abc/def/ghi"));
+            while (true)
+            {
+                client.Get();
+                await Task.Delay(TimeSpan.FromSeconds(5)).ConfigureAwait(false);
+            }
+        }
+    }
+}