code: function createKeywordWrapper(keywordsToRun) {
      var wrapper = function(next) {
          var args = _.rest(arguments);
          runner.run(keywordsToRun, keywords, args).then(next);
      };
      return wrapper;
  }
docs: Take `keywordsToRun` and wrap the run command
  into a function, which can used as a new keyword
  
  Usage:
  
  ```
  keywords["Login"] = createKeywordWrapper(
  "Go To Page", ["http://mysite.com/login"],
  "Fill In Credentials", ["user", "pa55w0rd"]
  "Click Element", ["#login-button"]
  );
  ```
  
  Now you can use the new `Login` keywords like this:
  
  key.run("Login").then( ... )