It's bad practice to use the admin user on Couchbase.

I propose that we @deprecate the current .withCredentials() method and add a new one named .withAdministratorCredentials(user, pass) as this more closely reflects what it actually is now.

And also introduce new method like so:

   .withLocalRBACUser(String username, String password, String roles)

The underlying API to support this can be found here: https://docs.couchbase.com/server/current/rest-api/rbac.html

Excerpt:

$ curl -X PUT --data "name=John Smith&roles=cluster_admin&password=jspassword" \
             -H "Content-Type: application/x-www-form-urlencoded" \
             http://Administrator:[email protected]:8091/settings/rbac/users/local/johnsmith