Add multi vault file map

[bbcVld]

I have to inventories:

inventory/staging/...
inventory/production/...

and to passwords file:

weak_password
strong_password

It will be useful if there is a settings which map vault file to password file:

"vault-files": {
  "inventory/staging/.../vault.yml": "weak_password"
  "inventory/production/.../vault.yml": "strong_password"
}