Security Group not provided for EC2 Module

At the moment, the example refers to:
aws_security_group.ec2_security_group.id

This is the security group to which the EC2 Belongs
This is not actually present anywhere and no other module provides this information.

## Proposed:

- Make the EC2 Module create it's own security group.
- Make a Security Group in the VPC.
- Make a separate module for Security Groups.