We occasionally have applications which need closing in a way which removes them from statistics and doesn't imply that the application was denied (i.e. 'not approved'). One such case is duplicate applications.

While administrators can remove applications through the admin interface, it's not an elegant option and can lead to other things breaking.

As part of this, any applications with 'invalid' status should not be included in metrics numbers/graphs/charts, and should not be listed on the Review pages.

• Add Invalid choice to the applications model status field
• Update Application queryset filters to exclude Invalid applications where appropriate
• Ensure that tests pass as expected