Updates test project to facilitate Azure DevOps tests

Author: joncloud

tests/https.Tests/https.Tests.csproj

@@ -1,18 +1,21 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp2.1</TargetFramework>
+    <TargetFramework>netcoreapp3.0</TargetFramework>
     <IsPackable>false</IsPackable>
     <RootNamespace>Https.Tests</RootNamespace>
     <LangVersion>preview</LangVersion>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.AspNetCore" Version="2.1.4" />
-    <PackageReference Include="Microsoft.AspNetCore.Hosting" Version="2.1.1" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.8.0" />
-    <PackageReference Include="xunit" Version="2.3.1" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.3.1" />
+    <PackageReference Include="Microsoft.AspNetCore" Version="2.2.0" />
+    <PackageReference Include="Microsoft.AspNetCore.Hosting" Version="2.2.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.2.0" />
+    <PackageReference Include="xunit" Version="2.4.1" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.1">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+    </PackageReference>
   </ItemGroup>
 
   <ItemGroup>