title: NightwatchJS .waitForElementPresent abortOnFailure not working
body: <p>I'm using NightwatchJS with NodeJS: <a href="http://nightwatchjs.org/api" rel="nofollow">http://nightwatchjs.org/api</a></p>
  
  <p>I have a modal dialog, which may or may not appear. It has a <code>#close_button</code> that needs to be clicked (if the modal does appear) to continue.</p>
  
  <p>I set the <code>abortOnFailure</code> parameter of <code>waitForElementPresent</code> to <code>false</code> so the script continues if the modal does not appear. However I can't get it to work.</p>
  
  <p>Any suggestions?</p>
  
  <pre><code>module.exports = {
      "Test" : function (browser) {
          browser
              .url("http://domain.com/")
              .waitForElementPresent('#close_button', 5000, false, function() {
                  this.click('#close_button')
              })
              .setValue('#username', 'test@email.com')
              //more code here
              .end(); //does end() go here or inside .waitForElementPresent() above?
      }
  }
  </code></pre>