Scrub @ mentions in Microsoft Teams

extractTextFromMessage.ts

private static extractTextFromMessage(message: builder.IMessage): string {
    var s = (message.text) ? message.text : '';
    if (message.entities) {
        message.entities.forEach((ent: any) => {
            s = s.replace(ent.text, '');
        })
    }
    return s.trim();
}