title: Enum for number in GraphQL (js)
body: <p>I want to allow one of the fields to be either 1, 2 or 3. I am not exactly sure how to do that in <a href="http://GraphQL-JS" rel="nofollow noreferrer">http://graphql.org/graphql-js/type/</a></p>
  
  <p>Because I would need to do something like:</p>
  
  <pre><code>var AgeType = new GraphQLEnumType({
    name: 'Age',
    values: {
      1: { value: 0 },
      2: { value: 1 },
      3: { value: 2 }
    }
  });
  </code></pre>
  
  <p>And this doesn't work because the key is a number...</p>