Currently when vault auto_inititialize [sic] is called a validation
step is run at the end to check that clients connected to vault
have the correct setup. However in sometimes there are no clients
to run validation with (as with cross model relation testing). To
facilitate this expose a new method 'auto_initialize_no_validation'
which skip the client validation.
Also correct the spelling of auto_inititialize but add a partial
to support tests that are already using the old spelling.