Upgrading the test project to net6.0.

Author: jooni91

tests/ReCaptcha.Tests/ReCaptcha.Tests.csproj

@@ -1,20 +1,21 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp3.1</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
 
     <IsPackable>false</IsPackable>
   </PropertyGroup>
 
   <ItemGroup>
     <PackageReference Include="Microsoft.AspNetCore.Mvc.ViewFeatures" Version="2.2.0" />
-    <PackageReference Include="Moq" Version="4.13.1" />
-    <PackageReference Include="nunit" Version="3.12.0" />
-    <PackageReference Include="NUnit3TestAdapter" Version="3.16.1">
+    <PackageReference Include="Moq" Version="4.17.2" />
+    <PackageReference Include="nunit" Version="3.13.3" />
+    <PackageReference Include="NUnit.ConsoleRunner" Version="3.15.0" />
+    <PackageReference Include="NUnit3TestAdapter" Version="4.2.1">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.5.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.1.0" />
   </ItemGroup>
 
   <ItemGroup>