title: Reset Vuetify form validation
body: <p>I have trouble resetting vuetify validation in v-dialog.</p>
  
  <p>This codepen is the simplified version of what I have.<br>
  <a href="https://codepen.io/yuukive/pen/BVqpEZ" rel="noreferrer">https://codepen.io/yuukive/pen/BVqpEZ</a></p>
  
  <p>With the code above, if I do </p>
  
  <p>(Open dialog --> press SAVE button --> (validation fails) --> press CLOSE button --> open dialog again),</p>
  
  <p>it is already validated when I open the dialog again...</p>
  
  <p>Is it possible to reset validation before a user opens it the 2nd time?</p>
  
  <pre class="lang-js prettyprint-override"><code>new Vue({
    el: '#app',
    data: () =&gt; ({
      dialog: false,
      emailRules: [v =&gt; !!v || 'Name is required']
    }),
    methods: {
      onSave() {
        if (!this.$refs.form.validate()) return
        dialog = false
      }
    }
  })
  </code></pre>
  
  <pre class="lang-html prettyprint-override"><code>&lt;div id="app"&gt;
    &lt;v-app id="inspire"&gt;
      &lt;v-layout row justify-center&gt;
        &lt;v-dialog v-model="dialog" persistent max-width="500px"&gt;
          &lt;v-btn slot="activator" color="primary" dark&gt;Open Dialog&lt;/v-btn&gt;
          &lt;v-card&gt;
            &lt;v-card-title&gt;
              &lt;span class="headline"&gt;Email&lt;/span&gt;
            &lt;/v-card-title&gt;
            &lt;v-form ref="form"&gt;
              &lt;v-card-text&gt;
                &lt;v-container grid-list-md&gt;
                  &lt;v-layout wrap&gt;
                    &lt;v-flex xs12&gt;
                      &lt;v-text-field label="Email" required :rules="emailRules"&gt;&lt;/v-text-field&gt;
                    &lt;/v-flex&gt;
                  &lt;/v-layout&gt;
                &lt;/v-container&gt;
                &lt;small&gt;*indicates required field&lt;/small&gt;
              &lt;/v-card-text&gt;
              &lt;v-card-actions&gt;
                &lt;v-spacer&gt;&lt;/v-spacer&gt;
                &lt;v-btn color="blue darken-1" flat @click.native="dialog = false"&gt;Close&lt;/v-btn&gt;
                &lt;v-btn color="blue darken-1" flat @click.native="onSave"&gt;Save&lt;/v-btn&gt;
              &lt;/v-card-actions&gt;
            &lt;/v-form&gt;
          &lt;/v-card&gt;
        &lt;/v-dialog&gt;
      &lt;/v-layout&gt;
    &lt;/v-app&gt;
  &lt;/div&gt;
  </code></pre>