title: How to move MKMapView based on selected annotation
body: <p>I have an MKMapView which populates the entirety of my view, but when a pin is selected, I am sliding up another view on top of the map. I want to move the map so the pin will appear in the centre of the visible area of the map.</p>
  
  <p>Difficult to explain but hopefully it makes sense! 
  Thanks in advance.</p>