Add support for .NET Core 3.1 (Azure Functions)

Author: Carl-Hugo

src/ForEvolve.OperationResults.AspNetCore/ForEvolve.OperationResults.AspNetCore.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net5.0</TargetFrameworks>
+    <TargetFrameworks>net5.0;netcoreapp3.1</TargetFrameworks>
     <Description>Extensions of ForEvolve.OperationResults ASP.NET Core. Adds support for ProblemDetails and includes a ModelBinderErrorActionFilter.</Description>
     <PackageTags>forevolve,aspnetcore,mvc,filters,asp.net,core,aspnet,asp,operation,result,results,message,exception,net5</PackageTags>
   </PropertyGroup>

src/ForEvolve.OperationResults/ForEvolve.OperationResults.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net5.0</TargetFrameworks>
+    <TargetFrameworks>net5.0;netcoreapp3.1</TargetFrameworks>
     <Description>Generic implementation of the operation result pattern that should fits most needs.</Description>
     <PackageTags>forevolve,aspnetcore,asp.net,core,aspnet,asp,operation,result,results,message,exception,net5</PackageTags>
   </PropertyGroup>