title: yup custom error messages not in ValidationError object
body: <p>The <a href="https://github.com/jquense/yup" rel="nofollow noreferrer">yup</a> <code>ValidationError</code> object doesn't have the custom error messages.</p>
  
  <pre class="lang-js prettyprint-override"><code>let data = {
      foo: "aaa"
  }
  
  let schema = 
      yup.object().shape({
          foo: yup.number().integer('Custom "must be a number" error message!')
      });
  
  try {
  
      let validated = await schema.validate(data, { abortEarly: false })
  
  } catch (err) {
      console.log(err.errors[0]) // foo must be a `number` type, but the final value was: `NaN`
      console.log(err.inner[0].message) // foo must be a `number` type, but the final value was: `NaN`
  }
  </code></pre>
  
  <p>I should get <code>Custom "must be a number" error message!</code> at <code>err.inner[0].message</code>.  </p>
  
  <p><a href="https://codesandbox.io/s/objective-chatelet-lpgi5?file=/src/index.js" rel="nofollow noreferrer">Here's the codesandbox.</a></p>
  
  <p>What am I doing wrong? <a href="https://leomotta.me/posts/data-validation-with-yup/" rel="nofollow noreferrer">I'm doing it as shown here.</a></p>