Removes a role from the Postgres Server

def _role_remove(name, user=None, host=None, port=None, maintenance_db=None,
                 password=None, runas=None):
    '''
    Removes a role from the Postgres Server
    '''

    # check if user exists
    if not user_exists(name, user, host, port, maintenance_db,
                       password=password, runas=runas):
        log.info('User \'%s\' does not exist', name)
        return False

    # user exists, proceed
    sub_cmd = 'DROP ROLE "{0}"'.format(name)
    _psql_prepare_and_run(
        ['-c', sub_cmd],
        runas=runas, host=host, user=user, port=port,
        maintenance_db=maintenance_db, password=password)

    if not user_exists(name, user, host, port, maintenance_db,
                       password=password, runas=runas):
        return True
    else:
        log.info('Failed to delete user \'%s\'.', name)
        return False