title: nightwatch failed to select element by its id
body: <p>I have below HTML dom on my page. And I use ngithwatch to write test cases. </p>
  
  <pre><code>&lt;td class="GPNWDJGHV" id="gwt-debug-MenuItem/mongo-true"&gt;Mongo Extension&lt;/td&gt;
  </code></pre>
  
  <p>If I use below code to select the dom's id, it will not find the element:</p>
  
  <pre><code>.waitForElementVisible('#gwt-debug-MenuItem/mongo-true', 10000)
  </code></pre>
  
  <p>but if I use classname it will works as below.</p>
  
  <pre><code>.waitForElementVisible('GPNWDJGHV', 10000)
  </code></pre>
  
  <p>the only different is that the id contains a character '/'. Is this the problem nightwatch not picking it up? What is the way to use id name with special character?</p>
  
  <p><strong>EDIT1</strong></p>
  
  <p>I have tried to add '\' in the id like below:</p>
  
  <pre><code>.waitForElementVisible('#gwt-debug-MenuItem\/mongo-true', 10000)
  </code></pre>
  
  <p>it still doesn't work. But this selector works in css. Not sure how different in nightwatch.</p>