func (client *Client) AddTagsToHost(host, source string, tags []string) error {
	uri := "/v1/tags/hosts/" + host
	if source != "" {
		uri += "?source=" + source
	}
	return client.doJsonRequest("POST", uri, reqGetHostTags{Tags: tags}, nil)
}
func (client *Client) AddTagsToHost(host, source string, tags []string) error {
	uri := "/v1/tags/hosts/" + host
	if source != "" {
		uri += "?source=" + source
	}
	return client.doJsonRequest("POST", uri, reqGetHostTags{Tags: tags}, nil)
}
// AddTagsToHost does exactly what it says on the tin. Given a list of tags,
// add them to the host. The source is optionally specified, and defaults to
// "users" as per the API documentation.