message: Fix signature of say and reply methods
diff: @@ -91,7 +91,7 @@ export class BotWorker {
  * @param message A string containing the text of a reply, or more fully formed message object
  * @returns Return value will contain the results of the send action, typically `{id: <id of message>}`
  */
  - public async say(message: Partial<BotkitMessage>): Promise<any> {
  + public async say(message: Partial<BotkitMessage> | string): Promise<any> {
  return new Promise((resolve, reject) => {
  let activity = this.ensureMessageFormat(message);
  @@ -122,7 +122,7 @@ export class BotWorker {
  * @param resp A string containing the text of a reply, or more fully formed message object
  * @returns Return value will contain the results of the send action, typically `{id: <id of message>}`
  */
  - public async reply(src: Partial<BotkitMessage>, resp: Partial<BotkitMessage>): Promise<any> {
  + public async reply(src: Partial<BotkitMessage>, resp: Partial<BotkitMessage> | string): Promise<any> {
  let activity = this.ensureMessageFormat(resp);
  // Get conversation reference from src
  @@ -253,7 +253,7 @@ export class BotWorker {
  * @params message a string or partial outgoing message object
  * @returns a properly formed Activity object
  */
  - public ensureMessageFormat(message: Partial<BotkitMessage>): Partial<Activity> {
  + public ensureMessageFormat(message: Partial<BotkitMessage> | string): Partial<Activity> {
  let activity: Partial<Activity> = {};
  if (typeof (message) === 'string') {
  