When namespace is missing, apps:destroy should delete from postgres db

[Cryptophobia]

From @Cryptophobia on June 26, 2017 15:11

There is an issue with the deis-controller when it comes to deleting applications. Let's say I create a new app in deis-controller called testing-app . The app is created in the data model for deis-controller and everything works correctly.

But let's say I am a kubernetes fanboi and I delete the the entire namespace (testing-app) of the application instead of using the good old deis-controller api to do the exact same job. This will no doubt achieve what I want because the application will disappear. However, when I query the api the application is still there. So the next thing I want to do is delete the application testing-app from deis using the deis apps:destroy -a testing-app or delete using DELETE on the v2/apps/testing-app route. However that call does not succeed because it does not find the namespace, when in reality everything is done for me, I just want this app to disappear from the deis db as well.

Is this as simple as adding more if logic that handle this case or am I missing something extra...?

Copied from original issue: deis/controller#1310