Update functionapp to .net core 3.1 (#212)

ServerlessLibraryFunctionApp/ServerLessLibraryFunctionApp.csproj

@@ -1,11 +1,11 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>netstandard2.0</TargetFramework>
-    <AzureFunctionsVersion>v2</AzureFunctionsVersion>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
+    <AzureFunctionsVersion>v3</AzureFunctionsVersion>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="Microsoft.Azure.WebJobs.Extensions.Storage" Version="3.0.1" />
-    <PackageReference Include="Microsoft.NET.Sdk.Functions" Version="1.0.24" />
+    <PackageReference Include="Microsoft.Azure.WebJobs.Extensions.Storage" Version="4.0.5" />
+    <PackageReference Include="Microsoft.NET.Sdk.Functions" Version="3.1.1" />
   </ItemGroup>
   <ItemGroup>
     <None Update="host.json">

ServerlessLibraryFunctionApp/UpdateCounts.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Threading.Tasks;
 using Microsoft.Azure.WebJobs;
 using Microsoft.Extensions.Logging;
 using Microsoft.WindowsAzure.Storage;
@@ -15,7 +16,7 @@ namespace ServerlessLibraryFunctionApp
 
         [FunctionName("UpdateCounts")]
         [Singleton]
-        public static async void Run([QueueTrigger("slitemstats")]string myQueueItemJson, [Table("slitemstats")] CloudTable table, ILogger log)
+        public static async Task Run([QueueTrigger("slitemstats")]string myQueueItemJson, [Table("slitemstats")] CloudTable table, ILogger log)
         {
             var payload = JsonConvert.DeserializeObject(((dynamic)myQueueItemJson));
             string id = payload.id.ToString();