title: How to auto assign public ip to EC2 instance with boto
body: <p>I have to start a new machine with <code>ec2.run_instances</code> in a given subnet but also to have a public ip auto assigned (not fixed elastic ip).</p>
  
  <p>When one starts a new machine from the Amazon's web EC2 Manager via the Request Instance (Instance details) there is a check-box called <strong>Assign Public IP</strong> to Auto-assign Public IP.
  See it highlighted in the screenshot:</p>
  
  <p><img src="https://i.stack.imgur.com/s6ZiC.png" alt="Request Instance wizard"> </p>
  
  <p>How can I achieve that check-box functionality with <code>boto</code>?</p>