awsutils: fix group traffic auth in create_group

Removed the cidr_ip kwarg and added the src_group_group_id kwarg to all
authorize_security_group calls when auth_group_traffic=True. Avoids
opening up all ports to the world for both VPC and non-VPC groups. This
issue was introduced by the recent VPC merge - it does not exist in the
latest stable release (0.94.3).

closes gh-341