Remove the need for a gvk override list

[dturn]

We dynamically determine the group/version/kind for pruning based on output of kubectl commands. However, there isn't a simple strategy that can do this correctly, so we maintain a an override list that is growing #696.

Ideally we'd be able to leverage kubeclient to determine valid GVKs. It looks like that will require adding some code in https://github.com/abonas/kubeclient to expose this information. If dont right this should also eliminate the need to manually build kubeclient instances based on paths / version https://github.com/Shopify/krane/blob/master/lib/krane/kubeclient_builder.rb#L19 . Instead kubeclient would have a new method that will give us an instance based on just a kind and its internal discovery mechanism would know the preferred group/version.

[dturn]

https://medium.com/@tannhauser.sphinx/bash-kubernetes-script-to-list-all-available-resources-subresources-c65a5c2c1173 might be helpful

[dturn]

Fixed in #778