title: disabled dates not updating on view when we add through button click
body: <p>I have used vue-hotel-date-picker its working fine. the issue is when using disabled dates props its disabled the dates first time when initializing and update on calendar.but when i update disabled dates array on any button click event it updates the disabled dates array but not reflect or render in view component. I have debug it through vuejs chrome extension.</p>
  
  <p>Here is an image when debugging
  <a href="https://i.stack.imgur.com/zgIu0.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/zgIu0.png" alt="enter image description here"></a></p>
  
  <p>plugin <a href="https://github.com/krystalcampioni/vue-hotel-datepicker" rel="nofollow noreferrer">link</a></p>
  
  <p>Here is my <strong>HTML</strong> Code</p>
  
  <pre><code>&lt;div class="box"&gt;
      &lt;h3&gt;Check in only on saturday and minimum stay of 10 days&lt;/h3&gt;
      &lt;DatePicker
        DatePickerID="01"
        :disabledDates = "disabledDates"
        :enableCheckout="true"
        :minNights="10"
        :useDummyInputs="false"
         placeholder="StartDate ► EndDate"
        /&gt;
    &lt;/div&gt;
    &lt;button @click="onChangeDisableDates()" &gt; Change Disable Dates &lt;/button&gt;
  </code></pre>
  
  <p><strong>JS</strong></p>
  
  <pre><code>&lt;script&gt;
  import DatePicker from 'components/HotelDatePicker.vue';
  
  export default {
      components: {
          DatePicker
      },
  
      data () {
        return {
           disabledDates : ['2017-08-18']
        }
      },
      methods : {
        onChangeDisableDates () {
           this.disabledDates.push("2017-08-19");
        }
      }
  };
  
  &lt;/script&gt;
  </code></pre>
  
  <p>I don't know how to figure out and solve this problem , it might be issue in this plugin,any help would be appreciated!</p>