Bot - Initiate action when new conversation begins

gistfile1.txt

bot.on('conversationUpdate', function (message) {
    if (message.membersAdded) {
        message.membersAdded.forEach(function (identity) {
            if (identity.id === message.address.bot.id) {
                bot.send(new builder.Message()
                    .address(message.address)
                    .text("Hello!  I'm a bot."));
            }
        });
    }
});