This fixes the acceptance tests by:
- Ensuring the fqdn_rand_string spec is passed undef as the second
parameter so that the seed is not used as the charset
- Ensuring the pw_hash spec is passed the key specifying the type of
hash, rather than the value that will be used to generate the
password
- Expecting puppet to report nil instead of empty string for undef
passwords
- Removing the fqdn_rand_base64 test because there is no such function
