title: managedObjectContext sent to instance error
body: <p>I am using core data to add data to my tableview from this tutorial </p>
  
  <p>"<a href="http://www.appcoda.com/introduction-to-core-data/" rel="nofollow noreferrer">http://www.appcoda.com/introduction-to-core-data/</a>" and </p>
  
  <p>I have no bugs, but when I click run I get this error
   -[AppDelegate managedObjectContext]: unrecognized selector sent to instance</p>
  
  <p>What does the error mean? Thanks</p>