Bump version number to 3.1

NatTypeTester/NatTypeTester.csproj

@@ -1,18 +1,22 @@
-<Project Sdk="Microsoft.NET.Sdk.WindowsDesktop">
+<Project Sdk="Microsoft.NET.Sdk.WindowsDesktop">
 
   <PropertyGroup>
     <OutputType>WinExe</OutputType>
     <TargetFramework>net48</TargetFramework>
     <UseWPF>true</UseWPF>
     <ApplicationIcon>icon.ico</ApplicationIcon>
-    <LangVersion>8</LangVersion>
-    <Version>3.0</Version>
+    <LangVersion>latest</LangVersion>
+    <Version>3.1</Version>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|AnyCPU'">
     <PlatformTarget>AnyCPU</PlatformTarget>
   </PropertyGroup>
 
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
+    <PlatformTarget>AnyCPU</PlatformTarget>
+  </PropertyGroup>
+
   <ItemGroup>
     <PackageReference Include="Costura.Fody" Version="4.1.0" />
     <PackageReference Include="ReactiveUI.Events.WPF" Version="11.5.17" />