message: resolve -> reject because semantics.
diff: @@ -112,7 +112,7 @@ export default React.createClass({
  this.setState({
  usernameError: _t('User names may only contain letters, numbers, dots, hyphens and underscores.'),
  });
  - return Promise.resolve();
  + return Promise.reject();
  }
  // Check if username is available
  