(GH-1602) exit 2 on items outdated

When items are outdated, the exit should indicate that it is not all
good to go as there is possible work to do. A zero exit code should
only be used if choco outdated does not return any results.

- Exit of 0 indicates all up to date
- Exit of 2 indicates out of date packages
- Exit of 1 or -1 would indicate an error

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

@@ -656,6 +656,11 @@ Output is package name | current version | available version | pinned?
                 }
             }
 
+            if (oudatedPackages.Count != 0 && Environment.ExitCode == 0)
+            {
+                Environment.ExitCode = 2;
+            }
+
             randomly_notify_about_pro_business(config);
         }