title: i18n vue is not working when changing locale, using rules in text field of vuetify
body: <p>Using Vuei18n and Vuetify make me confuse this point</p>
  
  <p>This is my code (I noted the weird thing in-line):</p>
  
  <pre><code>&lt;v-form @submit.prevent="login" v-model="valid" ref="form"&gt;
    &lt;v-text-field
      prepend-icon="person"
      name="login"
      :label="$t('Login')" &lt;-- This line is still translated automatically
      type="email"
      v-model="email"
      :rules="[v =&gt; !!v || $t('E-mail is required')]" &lt;-- This line is not translated automatically
    &gt;&lt;/v-text-field&gt;
    ...
  &lt;/v-form&gt;
  </code></pre>
  
  <p>How can I translate automatically the message under the input form?</p>