title: Geb wait for element to disappear
body: <p>When I perform an action on my page, a spinner is displayed which disappears once the action is completed. I want to wait for the spinner to disappear so as to execute the assert statements.</p>
  
  <p>I read the documentation which tells me how to wait for an element to appear but does not give info on how to wait for the element to disappear
  I don't know how to implement this in Cucumber, Geb, Groovy project.</p>