title: Validate that two keys of object should have same value using Joi?
body: <p>I am using <a href="https://www.npmjs.com/package/@hapi/joi" rel="nofollow noreferrer">Joi</a> for object dalidation.<br>
  suppose my object is  </p>
  
  <pre><code>// valid object
  object1 = {
      "minimum_balance": 200,
      "initial_amount": 200,
      "name": "Alok"
  }
  
  // invalid object
  object2 = {
      "minimum_balance": 250,
      "initial_amount": 200,
      "name": "Alok"
  }
  </code></pre>
  
  <p>I want to add validation to this object that <code>minimum_balance</code> and <code>initial_amount</code> should be same using <code>joi</code>. I should get error if values of both key are not same.</p>