title: change selected option of v-select using vue-test-util
body: <p>I'm trying to test a component builded with vuetify. For that I'm using vue-test-utils. My goal is to perform a change in the v-select field, and assert hat a mutation is performed. here is my code:</p>
  
  <pre><code>&lt;div id="app"&gt;
    &lt;v-app id="inspire"&gt;
      &lt;v-container fluid&gt;
        &lt;v-layout row wrap&gt;
          &lt;v-flex xs6&gt;
            &lt;v-subheader&gt;Standard&lt;/v-subheader&gt;
          &lt;/v-flex&gt;
          &lt;v-flex xs6&gt;
            &lt;v-select
              :items="items"
              v-model="e1"
              label="Select"
              single-line
            &gt;&lt;/v-select&gt;
          &lt;/v-flex&gt;
        &lt;/v-layout&gt;
      &lt;/v-container&gt;
    &lt;/v-app&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>The first test is ok when i set the data:</p>
  
  <pre><code>componentWrapper.setData({items: storesList})
  expect(componentWrapper.vm.$data.items).toHaveLength(2)
  </code></pre>
  
  <p>I now want to change the selected value I try: </p>
  
  <pre><code>componentWrapper.findAll('#option').at(1).setSelected()
  </code></pre>
  
  <p>And also</p>
  
  <pre><code>componentWrapper.find('el-select')
  </code></pre>
  
  <p>Can someone help me to retrieve the select and then change the selected value?
  Thanks for your support.</p>