Get credentials or prompt for them from options

def get_credentials(options, environment):
    """ Get credentials or prompt for them from options """
    if options['--username'] or options['--auth']:
        if not options['--username']:
            options['<username>'] = lib.prompt("Please enter the username for %s..." % environment)
        if not options['--password']:
            options['<password>'] = lib.prompt("Please enter the password for %s..." % environment, secret=True)
    return options