Update IoC registration for the filesystem

Author: bclothier

Rubberduck.Main/Root/RubberduckIoCInstaller.cs

@@ -61,6 +61,7 @@
 using Rubberduck.VBEditor.VbeRuntime;
 using Rubberduck.Parsing.Annotations;
 using Rubberduck.UI.Refactorings.AnnotateDeclaration;
+using System.IO.Abstractions;
 
 namespace Rubberduck.Root
 {
@@ -95,6 +96,7 @@ public void Install(IWindsorContainer container, IConfigurationStore store)
             ActivateAutoMagicFactories(container);
             OverridePropertyInjection(container);
 
+            RegisterFilesystem(container);
             RegisterInstances(container);
             RegisterAppWithSpecialDependencies(container);
             RegisterUnitTestingComSide(container);
@@ -1091,6 +1093,13 @@ private void RegisterAppWithSpecialDependencies(IWindsorContainer container)
                 .LifestyleSingleton());
         }
 
+        private void RegisterFileSystem(IWindsorContainer container)
+        {
+            container.Register(Component.For<IFileSystem>()
+                .ImplementedBy<FileSystem>()
+                .LifestyleSingleton());
+        }
+
         private void RegisterInstances(IWindsorContainer container)
         {
             container.Register(Component.For<IVBE>().Instance(_vbe));