message: change demo code to reflect limit of single word
  slack requires button label to be 1 word
diff: @@ -1000,7 +1000,7 @@ and using them with `bot.replyWithDialog`. These functions can be chained toget
  var dialog = bot.createDialog(
  'Title of dialog',
  'callback_id',
  - 'Button Label'
  + 'Submit'
  ).addText('Text','text','some text')
  .addSelect('Select','select',null,[{label:'Foo',value:'foo'},{label:'Bar',value:'bar'}],{placeholder: 'Select One'})
  .addTextarea('Textarea','textarea','some longer text',{placeholder: 'Put words here'})
  @@ -1131,7 +1131,7 @@ controller.on('interactive_message_callback', function(bot, trigger) {
  var dialog =bot.createDialog(
  'Title of dialog',
  'callback_id',
  - 'Button Label'
  + 'Submit'
  ).addText('Text','text','some text')
  .addSelect('Select','select',null,[{label:'Foo',value:'foo'},{label:'Bar',value:'bar'}],{placeholder: 'Select One'})
  .addTextarea('Textarea','textarea','some longer text',{placeholder: 'Put words here'})
  