title: Vee-validate independently validate components from parent without EventBus
body: <p>I would like to be able to validate all the components (with multiple fields) in my form independently from eachother using Vee-validate. </p>
  
  <p>I read <a href="https://stackoverflow.com/questions/41022935/validate-child-input-components-on-submit-with-vee-validate">this</a> topic. However, the solutions have all components be validated at the same time. I've tried using an EventBus (unsuccesfully) and I would prefer staying away from it. </p>
  
  <p>I have multi step form which should validate the current step before clicking 'continue'. Example:</p>
  
  <pre><code>-- Step 1
  ---- &lt;component-one /&gt; == component with fields 
  ---- (next button) &lt;-- validate content 1. If valid, go to step 2
  -- Step 2
  ---- &lt;component-two /&gt; == component with fields
  ---- (next button) &lt;-- validate content 2. If valid, go to step 2
  -- Step 3
  ---- &lt;component-three/&gt; == component with fields
  ---- (next button) &lt;-- validate content 3. If valid, go to step 3
  </code></pre>
  
  <p>My issue is that I have to call <code>this.validator</code> on component level to be able to validate the component. The continue button, however, lives on the parent level. I cannot create one shared <code>$validator</code> because then all steps have to be valid in order to continue (which is impossible)/ </p>