title: GraphQL large integer error: Int cannot represent non 32-bit signed integer value
body: <p>I´m trying to store a UNIX timestamp in <code>MongoDB</code> using <code>GraphQL</code>, but it seens that GraphQL has a limit to handle integers. See the mutation below:</p>
  
  <pre><code>const addUser = {
      type: UserType,
      description: 'Add an user',
      args: {
          data: {
              name: 'data',
              type: new GraphQLNonNull(CompanyInputType)
          }
      },
      resolve(root, params) {
  
          params.data.creationTimestamp = Date.now();
  
          const model = new UserModel(params.data);
          const saved = model.save();
  
          if (!saved)
              throw new Error('Error adding user');
  
          return saved;
      }
  }
  </code></pre>
  
  <p>Result:</p>
  
  <pre><code>  "errors": [
      {
        "message": "Int cannot represent non 32-bit signed integer value: 1499484833027",
        "locations": [
          {
            "line": 14,
            "column": 5
          }
        ],
        "path": [
          "addUser",
          "creationTimestamp"
        ]
      }
  </code></pre>
  
  <p>I´m currently using <code>GraphQLInteger</code> for this field on type definition:</p>
  
  <pre><code>creationTimestamp: { 
      type: GraphQLInt
  }
  </code></pre>
  
  <p>How can I solve that situation if there is no larger <code>GraphQLInt</code> available in <code>GraphQL</code> ?</p>