example for implements auth

[terryzwt]

Thanks for the contribute.

I would like to request example for the auth. thank you.

[codehakase]

@terryzwt

var DbClient *couchdb.Client

func couchdbAuth(username, password, server string) error {
    u, err := url.Parse(sever)
	if err != nil {
		return err
	}

	if username != "" {
		DbClient, err = couchdb.NewAuthClient(username, password, u)
	} else {
		DbClient, err = couchdb.NewClient(u)
	}
	if err != nil {
		return err
	}
}