Enable .NET assembly strong-name signing (#39)

* Update to .NET Core 3.1.101

Author: jeffkl

Directory.Build.props

@@ -4,5 +4,7 @@
     <DefaultItemExcludes>*log</DefaultItemExcludes>
     <MSBuildTreatWarningsAsErrors>true</MSBuildTreatWarningsAsErrors>
     <EnableDefaultNoneItems>false</EnableDefaultNoneItems>
+    <SignAssembly>true</SignAssembly>
+    <AssemblyOriginatorKeyFile>$(MSBuildThisFileDirectory)key.snk</AssemblyOriginatorKeyFile>
   </PropertyGroup>
 </Project>

MSBuildProjectCreator.sln

@@ -17,6 +17,7 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "build", "build", "{8339FD67
 		Directory.Build.rsp = Directory.Build.rsp
 		Directory.Build.targets = Directory.Build.targets
 		global.json = global.json
+		key.snk = key.snk
 		LICENSE = LICENSE
 		NuGet.config = NuGet.config
 		Packages.props = Packages.props

azure-pipelines.yml

@@ -4,7 +4,7 @@ resources:
 variables:
   BuildConfiguration: 'Debug'
   BuildPlatform: 'Any CPU'
-  DotNetCore3Version: '3.0.100'
+  DotNetCore3Version: '3.1.101'
   DotNetCore2Version: '2.1.802'
 
 trigger:
@@ -35,12 +35,12 @@ jobs:
     condition: and(succeeded(), startsWith(variables['Build.SourceBranch'], 'refs/tags/v'))
 
   - task: UseDotNet@2
-    displayName: 'Install .NET Core 2.0'
+    displayName: 'Install .NET Core $(DotNetCore2Version)'
     inputs:
       version: '$(DotNetCore2Version)'
 
   - task: UseDotNet@2
-    displayName: 'Install .NET Core 3.0'
+    displayName: 'Install .NET Core $(DotNetCore3Version)'
     inputs:
       version: '$(DotNetCore3Version)'
 

key.snk

@@ -5,5 +5,5 @@
 using System.Diagnostics.CodeAnalysis;
 using System.Runtime.CompilerServices;
 
-[assembly: InternalsVisibleTo("Microsoft.Build.Utilities.ProjectCreation.UnitTests")]
+[assembly: InternalsVisibleTo("Microsoft.Build.Utilities.ProjectCreation.UnitTests, PublicKey=00240000048000009400000006020000002400005253413100040000010001009d49923c182b255cf69ba155c3e5b2684b0f4794bd19129d7e693ac4609a70fa1791fff5353094ce6ab1be77e12278085b719bb11f74dbd282bb96b2647fab2497da04fa9f5a882089abb5c5fafa70b3f20a58265554e31602ec352b1e2e49831ff7afce904629911ebc39e22f8e06ec69dca2e68a4baa8a883965b2e992a7b4")]
 [assembly: SuppressMessage("StyleCop.CSharp.DocumentationRules", "SA1629:DocumentationTextMustEndWithAPeriod", Justification = "Reviewed.")]