Getting the path for ApprovalTests VisualStudioReporter from the registry.

VisualStudioReporter.cs

    public class VisualStudioReporter : GenericDiffReporter
    {
        private static readonly string DEVENV_REGISTRYKEY =
            @"HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\devenv.exe";
        private static readonly string PATH = (string)Registry.GetValue(DEVENV_REGISTRYKEY, "", @"Microsoft Visual Studio 11.0\Common7\IDE\devenv.exe"); 
        public static readonly VisualStudioReporter INSTANCE = new VisualStudioReporter();

        public VisualStudioReporter()
            : base(
                    PATH,
                    "/diff \"{0}\" \"{1}\"",
                    "Couldn't find Visual Studio at " + PATH)
        {
        }