Test against latest stable version

Author: GrahamTheCoder

Tests/Tests.csproj

@@ -26,8 +26,11 @@
   <ItemGroup>
     <ProjectReference Include="..\CommandLine\CodeConv.NetFramework\CodeConv.NetFramework.csproj" />
   </ItemGroup>
-  <ItemGroup Label="ReSharper test runner requirements">
-    <PackageReference Include="Microsoft.CodeAnalysis.Features" Version="3.11.0" />
+  <ItemGroup Label="ReSharper test runner requirements - test against latest Visual Studio version">
+    <PackageReference Include="Microsoft.CodeAnalysis.Features" Version="4.1.0" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="4.1.0" />
+    <PackageReference Include="Microsoft.CodeAnalysis.Workspaces.MSBuild" Version="4.1.0" />
+    <PackageReference Include="Microsoft.CodeAnalysis.VisualBasic.Workspaces" Version="4.1.0" />
     <PackageReference Include="Microsoft.Build" Version="17.0.0" />
     <PackageReference Include="Microsoft.Build.Tasks.Core" Version="17.0.0" />
   </ItemGroup>