title: change tab bar item image in swift programatically
body: <p>I am working on an app in Xcode. I currently have three tabBarItems on my tab bar. I want the middle one to be a picture chosen by the user. I have the desired picture in a variable and i have the tabbar.swift set up to put the code in. I just need to set the image to the variables image with correct size (and make the picture appear as a circle) and the title name to a string. 
  Any help in doing this would be much appreciated. Thanks</p>