Gets the related tags for given tag.

def tags_getrelated(tag):
    """Gets the related tags for given tag."""
    method = 'flickr.tags.getRelated'
    data = _doget(method, auth=False, tag=tag)
    if isinstance(data.rsp.tags.tag, list):
        return [tag.text for tag in data.rsp.tags.tag]
    else:
        return [data.rsp.tags.tag.text]