provider/aws: ElastiCache test updates

- rename test to have _basic suffix, so we can run it individually
- use us-east-1 for basic test, since that's probably the only region that has
  Classic
- update the indexing of nodes; cache nodes are 4 digits

builtin/providers/aws/resource_aws_elasticache_cluster_test.go

@@ -12,7 +12,7 @@ import (
 	"github.com/hashicorp/terraform/terraform"
 )
 
-func TestAccAWSElasticacheCluster(t *testing.T) {
+func TestAccAWSElasticacheCluster_basic(t *testing.T) {
 	resource.Test(t, resource.TestCase{
 		PreCheck:     func() { testAccPreCheck(t) },
 		Providers:    testAccProviders,
@@ -24,7 +24,7 @@ func TestAccAWSElasticacheCluster(t *testing.T) {
 					testAccCheckAWSElasticacheSecurityGroupExists("aws_elasticache_security_group.bar"),
 					testAccCheckAWSElasticacheClusterExists("aws_elasticache_cluster.bar"),
 					resource.TestCheckResourceAttr(
-						"aws_elasticache_cluster.bar", "cache_nodes.0.id", "001"),
+						"aws_elasticache_cluster.bar", "cache_nodes.0.id", "0001"),
 				),
 			},
 		},
@@ -95,6 +95,9 @@ func genRandInt() int {
 }
 
 var testAccAWSElasticacheClusterConfig = fmt.Sprintf(`
+provider "aws" { 
+	region = "us-east-1"
+}
 resource "aws_security_group" "bar" {
     name = "tf-test-security-group-%03d"
     description = "tf-test-security-group-descr"