title: Node.js joi - .number() fails to pas 0
body: <p>I have this joi schema using .number() for a body parameter 'public'</p>
  
  <pre><code>contactSchema: Joi.object().keys({
      email: Joi.string().email().required(),
      public: Joi.number().required()
  }),
  </code></pre>
  
  <p>If I allow the paremeter to be 0 in some instance ...</p>
  
  <pre><code>if(req.session.sessionEmail){
      var isPublic = 0;
    } else {
      var isPublic = 1;
    }
  </code></pre>
  
  <p>... joi says its invalid. </p>
  
  <p>If I don't pass a 0 ... all is good?</p>
  
  <pre><code>if(req.session.sessionEmail){
      var isPublic = 2;
    } else {
      var isPublic = 1;
    }
  </code></pre>
  
  <p>Why does it fail in case of 0?    </p>
  
  <p><a href="https://github.com/hapijs/joi/blob/master/API.md#number---inherits-from-any" rel="nofollow noreferrer">https://github.com/hapijs/joi/blob/master/API.md#number---inherits-from-any</a></p>