Launches a new server instance.

def create(self):
        """Launches a new server instance."""
        self.server_attrs = self.consul.create_server(
                "%s-%s" % (self.stack.name, self.name),
                self.disk_image_id,
                self.instance_type,
                self.ssh_key_name,
                tags=self.tags,
                availability_zone=self.availability_zone,
                timeout_s=self.launch_timeout_s,
                security_groups=self.security_groups,
                **self.provider_extras
                )
        log.debug('Post launch delay: %d s' % self.post_launch_delay_s)
        time.sleep(self.post_launch_delay_s)