Add egress rule to SG for TF 0.5 compat

See "NOTE on Egress rules" here http://www.terraform.io/docs/providers/aws/r/security_group.html

As reported here: https://github.com/hashicorp/terraform/issues/1873

terraform/aws/consul.tf

@@ -62,4 +62,12 @@ resource "aws_security_group" "consul" {
         protocol = "tcp"
         cidr_blocks = ["0.0.0.0/0"]
     }
+    
+    // This is for outbound internet access
+    egress {
+        from_port = 0
+        to_port = 0
+        protocol = "-1"
+        cidr_block = "0.0.0.0/0"
+    }
 }