title: Dynamically update one dropdown by using another in Vue 2.1
body: <p>I have a form built in Vue v.2 with an address section. I'm trying to get the State dropdown to autopopulate based on what's selected in the city. When a user selects 'Atlanta', 'Georgia' should show in the state dropdown. This seems like it should be pretty simple, especially since I'm using jQuery. I tried to implement <a href="https://stackoverflow.com/questions/499405/change-the-selected-value-of-a-drop-down-list-with-jquery">this solution</a> which was able to log out the correct state, but the dropdown would still show "*State".  I have to be missing something simple here.</p>
  
  <pre><code> &lt;div class="grid-33 city"&gt;
     &lt;select name="business-address-city"
             v-model="bi.addresses.business.city"
             @change="updateCityState(bi.addresses.business.city)&gt;
       &lt;option value=""&gt;*City&lt;/option&gt;
       &lt;option value="Atlanta"&gt;Atlanta&lt;/option&gt;
       &lt;option value="Houston"&gt;Houston&lt;/option&gt;
       &lt;option value="Los Angeles"&gt;Los Angeles&lt;/option&gt;
       &lt;option value="Miami"&gt;Miami&lt;/option&gt;
       &lt;option value="Minneapolis"&gt;Minneapolis&lt;/option&gt;
     &lt;/select&gt;
   &lt;/div&gt;
  
   &lt;div class="grid-33 state"&gt;
     &lt;select name="business-address-state" v-model="bi.addresses.business.state"&gt;
       &lt;option value=""&gt;*State&lt;/option&gt;
       &lt;option value="California"&gt;California&lt;/option&gt;
       &lt;option value="Florida"&gt;Florida&lt;/option&gt;
       &lt;option value="Georgia"&gt;Georgia&lt;/option&gt;
       &lt;option value="Minnesota"&gt;Minnesota&lt;/option&gt;
       &lt;option value="Texas"&gt;Texas&lt;/option&gt;
     &lt;/select&gt;
   &lt;/div&gt;
  
  
  data () {
    return {
      bi: businessInfo,
      checked: true
    }
  },
  watch: {
    bi.addresses.business.city: function () {
      if ($('[name="business-address-city"]').val() == 'Atlanta') {
        $('[name="business-address-state"]').val('Georgia').change()
      }
    }
  },
  methods: {
    updateCityState (e) {
      var city = e
      var state = $('[name="business-address-state"]')
      console.log(state);
      switch (city) {
        case 'Atlanta':
          $('[name="business-address-state"] options').val('Georgia').change()
          break
        case 'Houston':
          state = 'Texas'
          break
        case 'Los Angeles':
          state = 'California'
          break
        case 'Miami':
          state = 'Florida'
          break
        case 'Minneapolis':
          state = 'Minnesota'
          break
      }
    }
  }
  </code></pre>