message: fix(types): addSelect param types
  Changing option_list to an array of object.
diff: @@ -189,7 +189,7 @@ export class SlackDialog {
  * @param option_list
  * @param options
  */
  - public addSelect(label: string, name: string, value: string, option_list: string, options?: any): SlackDialog {
  + public addSelect(label: string, name: string, value: string, option_list: [{label: string, value: string}], options?: any): SlackDialog {
  var element = {
  label: label,
  name: name,
  