fix usage syntax of data.aws_availability_zones... (#16)

Author: tamsky

aws/backing-services/aurora-postgres.tf

@@ -51,7 +51,7 @@ module "aurora_postgres" {
   db_name            = "${var.POSTGRES_DB_NAME}"
   db_port            = "5432"
   vpc_id             = "${module.vpc.vpc_id}"
-  availability_zones = ["${data.aws_availability_zones.available}"]
+  availability_zones = ["${data.aws_availability_zones.available.names}"]
   subnets            = ["${module.subnets.private_subnet_ids}"]
   zone_id            = "${var.zone_id}"
   security_groups    = ["${module.kops_metadata.nodes_security_group_id}"]

aws/backing-services/elasticache-redis.tf

@@ -34,7 +34,7 @@ module "elasticache_redis" {
   alarm_cpu_threshold_percent  = "75"
   alarm_memory_threshold_bytes = "10000000"
   apply_immediately            = "true"
-  availability_zones           = ["${data.aws_availability_zones.available}"]
+  availability_zones           = ["${data.aws_availability_zones.available.names}"]
   automatic_failover           = "false"
   enabled                      = "${var.REDIS_CLUSTER_ENABLED}"
 }

aws/backing-services/vpc.tf

@@ -12,7 +12,7 @@ module "vpc" {
 
 module "subnets" {
   source              = "git::https://github.com/cloudposse/terraform-aws-dynamic-subnets.git?ref=tags/0.3.4"
-  availability_zones  = ["${data.aws_availability_zones.available}"]
+  availability_zones  = ["${data.aws_availability_zones.available.names}"]
   namespace           = "${var.namespace}"
   stage               = "${var.stage}"
   name                = "${local.name}"