title: Creating a 3x3 grid with auto layout constraints
body: <p>Xcode has said there are no layout issues but as you can see there is. I have tried everything. Apple docs, YouTube, Google, etc. It seems I am doing it right however maybe the order I'm doing things in or something else is causing these issues. After trying everything I finally let Xcode <code>add missing constraints</code> and it's the best result so far. I have 9 buttons onto of 9 UIImages so I have to do the same thing I do to the buttons as I do with the UIImages. I have temporarily placed the UIImages on top of the buttons so I can see what I'm doing more easily. I've got 2 screenshots. Please advise. </p>
  
  <p>Beginning</p>
  
  <p><img src="https://i.stack.imgur.com/S35Kz.png" alt="Beginning"></p>
  
  <p>This is after using Xcode's <code>add missing constraints</code> option. 
  Sorta what I want but no cigar.</p>
  
  <p><img src="https://i.stack.imgur.com/vb3yZ.png" alt="enter image description here"></p>