Vault-storage plugin cant read certs stored in vault

[bsamsom]

When trying to pull a cert from vault we get a:
Option key_cert is required, but storage value from "PATH/cert" could not be read.

it looks like the vault-storage plugin cant see any public/private keys stored in vault, which is kind of annoying if you are trying to use something like oauth for authentication in a script as it requires a private key.

based on:
Secure † Password input, value exposed in scripts and commands.
Secure Remote Authentication † Password input, value not exposed in scripts or commands, used only by Node Executors for authentication.

I take it this is a feature request as it does mention password input and certs are not passwords.