title: adding tests to ionic v3 prior to v4 upddate
body: <p>I have a (complicated, live, in production) ionic app that is currently on ionic-angular 3.9.2 but has been around since (I think) the v1 days.  There are no tests (yikes).</p>
  
  <p>I see that Ionic 4 ships with some e2e testing support which is great, but does me little good since it's not compatible with the version that I'm on.</p>
  
  <p>I'd like to get some e2e tests in place prior to biting the bullet and migrating up to v4 and all the many changes that will entail.</p>
  
  <p>Are there any resources available that can help me add tests to a v3 app in a way that will be compatible with v4 as I go through the update process?</p>