add cf security group
add an SG for CF
Merge branch 'feature/terraform-aws-vpc' of github.com:cloudfoundry-community/terraform-cf-aws-vpc into feature/terraform-aws-vpc
cleanup the aws-vpc.tf file
Merge branch 'feature/terraform-aws-vpc' of github.com:cloudfoundry-community/terraform-cf-aws-vpc into feature/terraform-aws-vpc
allow ICMP through the NAT instance