code: function translate(words) {
    return function(req, res) {
      if (req.params.complete) {
        return res.send(Object.keys(words).join(' '));
      }
      res.send(words[req.params[1]]);
    };
  }
docs: Returns a simple middleware that will look up a key
  in `words` and print the value. This middleware also
  supports completion by looking for the `--complete`
  flag and prints the available keys. We'll use this
  to translate a few terms in both spanish and emoji.