title: Joi validation and pattern
body: <p>Hello I am trying to make a composite Joi validation but I fail.</p>
  
  <p>What I am trying to validate is the following object:</p>
  
  <pre><code>    {
        content: {
          dynamicKeyName: {
            title: '1',
            link: 'ggdf',
            order: 1,
          },
          dynamicKeyName2: {
            title: 'tttt',
            link: 'bbbb',
            order: 2,
          },
          .
          .
          .
        }
      }
  </code></pre>
  
  <p>I am trying to create a validation rule that will have many sub objects like the dynamicKeyName object without knowing the exact key name but to have similar value object.</p>
  
  <p>I have written the following Joi rules:</p>
  
  <pre><code>const subSchema = Joi.object().required().keys({
    title: Joi.string().required(),
    link: Joi.string().required(),
    order: Joi.number().integer().required(),
  });
  
  const schema = Joi.object().keys({
    content: Joi.object().pattern(/^[\w\d]+$/, subSchema),
    .
    .
    .
  });
  </code></pre>
  
  <p>However when I run the validation I get an error of: "additional property dynamicKeyName should NOT have additional properties"</p>