Migrate tests to netcoreapp3.1

appveyor.yml

@@ -1,5 +1,5 @@
 version: 1.0.{build}
-os: Visual Studio 2017
+os: Visual Studio 2019
 
 branches:
   only:

src/NReco.LambdaParser.Tests/NReco.LambdaParser.Tests.csproj

@@ -1,14 +1,8 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp1.0</TargetFramework>
-    <AssemblyName>NReco.LambdaParser.Tests</AssemblyName>
-    <PackageId>NReco.LambdaParser.Tests</PackageId>
-    <GenerateRuntimeConfigurationFiles>true</GenerateRuntimeConfigurationFiles>
-    <PackageTargetFallback>$(PackageTargetFallback);portable-net451+win8;dnxcore50;netstandard1.6</PackageTargetFallback>
-    <GenerateAssemblyConfigurationAttribute>false</GenerateAssemblyConfigurationAttribute>
-    <GenerateAssemblyCompanyAttribute>false</GenerateAssemblyCompanyAttribute>
-    <GenerateAssemblyProductAttribute>false</GenerateAssemblyProductAttribute>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
+    <IsPackable>false</IsPackable>  
   </PropertyGroup>
 
   <ItemGroup>
@@ -17,12 +11,8 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.0.0" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.2.0" />
     <PackageReference Include="xunit" Version="2.2.0" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.2.0" />
   </ItemGroup>
 
-  <PropertyGroup Condition=" '$(TargetFramework)' == 'netcoreapp1.0' ">
-    <DebugType>portable</DebugType>
-  </PropertyGroup>
-
-</Project>
+</Project>