API: make Vault.from exceptions unchecked #78
Description
Errors that can occur during the execution of the Vault.from family of methods are mostly configuration errors on the developer's side and should likely be implemented as a RuntimeException subtype so as to make vault's API usage smoother (for instance if used in a static block, or when drafting small scripts).
The Vault instance remains an AutoCloseable so this will not entirely remove the use for a try-with setup, but it gives some added flexibility.