Add get all command

[djfarrelly]

Purpose

Instead of having to switch back and forth between kubectl and kubsecret it would be awesome to quickly list all secrets in a given namespace.

Idea

Instead of having to run kubectl -n reply get secrets then run kubesecret -n reply get secret <secret-name> we could list all of the secrets via kubesecret to have a smooth workflow.

If we wanted to make it more interactive one day we could even make it put out a numbered list and prompt the user for a number to read. ex.

kubesecret -n reply get
1) secret-a
2) secret-b
What secret would you like to view?
> _