Fix BuildIntegrationTests to use MSBuildLocation before ctor

The BuildIintegrationTests.ctor itself loads MSBuild when jitting, so we need xunit to invoke the msbuild locator before that. We achieve this with a class fixture.

Author: AArnott

src/NerdBank.GitVersioning.Tests/AssemblyInfoTest.cs

@@ -6,13 +6,8 @@
 using Nerdbank.GitVersioning.Tasks;
 using Xunit;
 
-public class AssemblyInfoTest
+public class AssemblyInfoTest : IClassFixture<MSBuildFixture>
 {
-    public AssemblyInfoTest()
-    {
-        MSBuildExtensions.LoadMSBuild();
-    }
-
     [Fact]
     public void FSharpGenerator()
     {

src/NerdBank.GitVersioning.Tests/BuildIntegrationTests.cs

@@ -23,7 +23,7 @@
 using Xunit.Abstractions;
 using Version = System.Version;
 
-public class BuildIntegrationTests : RepoTestBase
+public class BuildIntegrationTests : RepoTestBase, IClassFixture<MSBuildFixture>
 {
     private const string GitVersioningTargetsFileName = "NerdBank.GitVersioning.targets";
     private const string UnitTestCloudBuildPrefix = "UnitTest: ";
@@ -48,8 +48,6 @@ public class BuildIntegrationTests : RepoTestBase
     public BuildIntegrationTests(ITestOutputHelper logger)
         : base(logger)
     {
-        MSBuildExtensions.LoadMSBuild();
-
         int seed = (int)DateTime.Now.Ticks;
         this.random = new Random(seed);
         this.Logger.WriteLine("Random seed: {0}", seed);

src/NerdBank.GitVersioning.Tests/MSBuildFixture.cs

@@ -0,0 +1,7 @@
+public class MSBuildFixture
+{
+    public MSBuildFixture()
+    {
+        MSBuildExtensions.LoadMSBuild();
+    }
+}