Keep CA happy

Author: jcansdale

src/GitHub.VisualStudio/Services/UsageService.cs

@@ -16,7 +16,7 @@
 namespace GitHub.Services
 {
     [Export(typeof(IUsageService))]
-    public class UsageService : IUsageService
+    public sealed class UsageService : IUsageService, IDisposable
     {
         const string StoreFileName = "metrics.json";
         const string UserStoreFileName = "user.json";
@@ -37,6 +37,11 @@ public UsageService(IGitHubServiceProvider serviceProvider, IEnvironment environ
             this.environment = environment;
         }
 
+        public void Dispose()
+        {
+            writeSemaphoreSlim.Dispose();
+        }
+
         public async Task<Guid> GetUserGuid()
         {
             await Initialize();