Move test project to net5.0.

Author: 333fred

.github/workflows/ci.yml

@@ -17,10 +17,10 @@ jobs:
     - name: Setup virtual display
       run: /usr/bin/Xvfb :99 -screen 0 1024x768x24 > /dev/null 2>&1 &
 
-    - name: Install .NET Core 3.1 SDK
+    - name: Install .NET Core 5.0 SDK
       uses: actions/[email protected]
       with:
-        dotnet-version: 3.1.x
+        dotnet-version: 5.0.x
 
     - name: Install Node.js 15.x
       uses: actions/setup-node@v1

test/integrationTests/testAssets/slnWithCsproj/src/app/app.csproj

@@ -5,7 +5,7 @@
  </ItemGroup>
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp2.1</TargetFramework>
+    <TargetFramework>net5.0</TargetFramework>
   </PropertyGroup>
 
 </Project>