(GH-304) Auto Installer allow system cleanup

If the preceeding chocolatelyUninstall.ps1 uninstalls an application,
sometimes the system is still cleaning up files and registry keys.
Those keys are found by the auto installer and it decides to also move
forward with the uninstall. In cases like that, the auto uninstaller
should wait a few seconds before moving forward with checks.

src/chocolatey/infrastructure.app/services/AutomaticUninstallerService.cs

@@ -18,6 +18,7 @@ namespace chocolatey.infrastructure.app.services
     using System;
     using System.Collections.Generic;
     using System.Linq;
+    using System.Threading;
     using configuration;
     using domain;
     using filesystem;
@@ -30,6 +31,7 @@ public class AutomaticUninstallerService : IAutomaticUninstallerService
         private readonly IFileSystem _fileSystem;
         private readonly IRegistryService _registryService;
         private readonly ICommandExecutor _commandExecutor;
+        private const int SLEEP_TIME = 5;
 
         public AutomaticUninstallerService(IChocolateyPackageInformationService packageInfoService, IFileSystem fileSystem, IRegistryService registryService, ICommandExecutor commandExecutor)
         {
@@ -63,6 +65,8 @@ public void run(PackageResult packageResult, ChocolateyConfiguration config)
             }
 
             this.Log().Info(" Running auto uninstaller...");
+            this.Log().Debug("Sleeping for {0} seconds to allow Windows to finish cleaning up.".format_with(SLEEP_TIME));
+            Thread.Sleep((int)TimeSpan.FromSeconds(SLEEP_TIME).TotalMilliseconds);
 
             foreach (var key in registryKeys.or_empty_list_if_null())
             {