Lock an instance

    instance_id
        ID of the instance to be locked

    CLI Example:

    .. code-block:: bash

        salt '*' nova.lock 1138

def lock(instance_id, profile=None, **kwargs):
    '''
    Lock an instance

    instance_id
        ID of the instance to be locked

    CLI Example:

    .. code-block:: bash

        salt '*' nova.lock 1138

    '''
    conn = _auth(profile, **kwargs)
    return conn.lock(instance_id)