title: Use v_for without v-bind:key as shown in the docs?
body: <p>The vue docs <a href="https://v2.vuejs.org/v2/guide/list.html" rel="nofollow noreferrer">https://v2.vuejs.org/v2/guide/list.html</a> say I can do this:</p>
  <pre><code>&lt;div v-for=&quot;(value, name) in object&quot;&gt;
    {{ name }}: {{ value }}
  &lt;/div&gt;
  </code></pre>
  <p>But when I do that I get:</p>
  <pre><code>Module Error (from ./node_modules/eslint-loader/index.js):
  
    7:5  error  Elements in iteration expect to have 'v-bind:key' directives  vue/require-v-for-key
  </code></pre>
  <p>I can work around by saying</p>
  <pre><code>    &lt;div v-for=&quot;(value, name) in object&quot; v-bind:key=&quot;name&quot;&gt;
  </code></pre>
  <p>Are the docs wrong? What am I missing?</p>
  <pre><code>air:v0 crb$ vue --version
  @vue/cli 4.5.6
  </code></pre>
  <p>Command is 'npm run serve' which runs 'vue-cli-service serve'</p>
  <p>The whole file:</p>
  <pre><code>&lt;template&gt;
    &lt;div class=&quot;foo&quot;&gt;
      &lt;h1&gt;foo Component&lt;/h1&gt;
      &lt;!--
      &lt;div v-for=&quot;(value, name) in object&quot; v-bind:key=&quot;name&quot;&gt;
      --&gt; 
      &lt;div v-for=&quot;(value, name) in object&quot;&gt;
        {{ name }}: {{ value }}
      &lt;/div&gt;
    &lt;/div&gt;
  &lt;/template&gt;
  
  &lt;script&gt;
    export default {
          data() {
                  return {
                          object: { 'a': 1, 'b': 2 }
                  }
          }
    }
  &lt;/script&gt;
  </code></pre>