message: Use GraphQL printer
  Borrow the technique used in `utilities/schemaPrinter.js` for printing default values - otherwise strings, arrays, or objects would not be rendered correctly.
diff: */
  import React, { PropTypes } from 'react';
  +import { astFromValue, print } from 'graphql';
  import TypeLink from './TypeLink';
  export default class Argument extends React.Component {
  @@ -28,7 +29,7 @@ export default class Argument extends React.Component {
  <span>
  {' = '}
  <span className="arg-default-value">
  - { arg.defaultValue === '' ? '""' : arg.defaultValue }
  + {print(astFromValue(arg.defaultValue, arg.type))}
  </span>
  </span>
  }
  