Feature request to add testing username/password to idm tool

Right now we have no way to test if a user/password combination works with idm tool. This is important because when we run a configuration tool like puppet, we are forced to reconfigure a user's password on subsequent puppet runs because we have no way to tell if the desired password is already configured for this user. It would be really helpful if we could use idmtool to test a login and to see if the desired password is already set for that user.