Updated .NET Core apps to LTR 3.1

All downstream implementors should already be using .NET Core 3.x.

Author: JeremyCaney

OnTopic.AspNetCore.Mvc.Host/OnTopic.AspNetCore.Mvc.Host.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk.Web">
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp3.0</TargetFramework>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
     <UserSecretsId>62eb85bf-f802-4afd-8bec-3d344e1cfc79</UserSecretsId>
     <IsPackable>false</IsPackable>
   </PropertyGroup>

OnTopic.AspNetCore.Mvc.Tests/OnTopic.AspNetCore.Mvc.Tests.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp3.0</TargetFramework>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
     <IsPackable>false</IsPackable>
     <LangVersion>9.0</LangVersion>
   </PropertyGroup>

OnTopic.AspNetCore.Mvc/OnTopic.AspNetCore.Mvc.csproj

@@ -3,7 +3,7 @@
   <PropertyGroup>
     <ProjectGuid>{B7F136A1-C86D-4A74-AC4F-3693CD1358A4}</ProjectGuid>
     <RootNamespace>OnTopic.AspNetCore.Mvc</RootNamespace>
-    <TargetFramework>netcoreapp3.0</TargetFramework>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
     <ShouldCreateLogs>True</ShouldCreateLogs>
     <AdvancedSettingsExpanded>False</AdvancedSettingsExpanded>
     <LangVersion>9.0</LangVersion>

OnTopic.Tests/OnTopic.Tests.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp3.0</TargetFramework>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
     <IsPackable>false</IsPackable>
     <NoWarn>CS1591,1701,1702,CA1707,CA1062,CS8602,CS8604;CA1303;IDE0059</NoWarn>
     <LangVersion>9.0</LangVersion>