(chore) Upgrade .NET SDK and NuGet packages (#44)

Author: dfederm

Directory.Packages.props

@@ -4,13 +4,13 @@
   </PropertyGroup>
   <ItemGroup>
     <PackageVersion Include="CommandLineParser" Version="2.9.1" />
-    <PackageVersion Include="log4net" Version="2.0.15" />
-    <PackageVersion Include="Microsoft.Build" Version="17.5.0" />
-    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.5.0" />
-    <PackageVersion Include="NuGet.Commands" Version="6.5.0" />
+    <PackageVersion Include="log4net" Version="2.0.17" />
+    <PackageVersion Include="Microsoft.Build" Version="17.10.4" />
+    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.10.0" />
+    <PackageVersion Include="NuGet.Commands" Version="6.10.1" />
     <PackageVersion Include="Shouldly" Version="4.2.1" />
-    <PackageVersion Include="xunit" Version="2.4.2" />
-    <PackageVersion Include="xunit.runner.visualstudio" Version="2.4.5" />
+    <PackageVersion Include="xunit" Version="2.9.0" />
+    <PackageVersion Include="xunit.runner.visualstudio" Version="2.8.2" />
   </ItemGroup>
   <ItemGroup>
     <GlobalPackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" />

global.json

@@ -1,6 +1,6 @@
 {
     "sdk": {
-        "version": "7.0.100",
+        "version": "8.0.100",
         "rollForward": "latestMinor"
     }
 }