text: module.exports = ( req, res, next ) => {
  
    const email = req.param( 'email' );
  
    User.findOne({ email }).exec( ( err, user ) => {
    
      if( err )
        return res.serverError( 'error finding user' );
  
      if( user )
        return res.badRequest( 'user already exists' );
  
      return next();
  
    })
  }
  