examples/basic/main.tf: Add usage of "root_block_device" (#18) (#65)

Author: jjardon

examples/basic/main.tf

@@ -64,6 +64,11 @@ module "ec2" {
   subnet_id                   = "${element(data.aws_subnet_ids.all.ids, 0)}"
   vpc_security_group_ids      = ["${module.security_group.this_security_group_id}"]
   associate_public_ip_address = true
+
+  root_block_device = [{
+    volume_type           = "gp2"
+    volume_size           = 10
+  }]
 }
 
 module "ec2_with_t2_unlimited" {