Can't read values from external (non vault-cli) sources

[mgu]

vault-cli has been designed read and write all the values in a "value" key.

With the kv1 secret engine, vault set a b will put this kind of secret in the vault :

data:
  value: b

But some values from external sources (e.g. the rabbitmq secret engine) have this kind of secret :

data:
  username: foo
  password: bar

The current version (0.8.0) can't read such values (and fails with a KeyError).
It would be great to handle such values (in get/get-all operations) and return the "data" dict directly