Get redis keys, supports glob style patterns

    CLI Example:

    .. code-block:: bash

        salt '*' redis.keys
        salt '*' redis.keys test*

def keys(pattern='*', host=None, port=None, db=None, password=None):
    '''
    Get redis keys, supports glob style patterns

    CLI Example:

    .. code-block:: bash

        salt '*' redis.keys
        salt '*' redis.keys test*
    '''
    server = _connect(host, port, db, password)
    return server.keys(pattern)