Deregister an AMI by id
        :param ami_id:
        :param region: region to deregister from
        :return:

def deregister_image(self, ami_id, region='us-east-1'):
        """
        Deregister an AMI by id
        :param ami_id:
        :param region: region to deregister from
        :return:
        """
        deregister_cmd = "aws ec2 --profile {} --region {} deregister-image --image-id {}"\
            .format(self.aws_project, region, ami_id)
        print "De-registering old image, now that the new one exists."
        print "De-registering cmd: {}".format(deregister_cmd)
        res = subprocess.check_output(shlex.split(deregister_cmd))
        print "Response: {}".format(res)
        print "Not monitoring de-register command"