Merge pull request #4020 from stack72/f-aws-elasticache-cluster-maintenance-window

provider/aws:Elasticache maintenance_window forces lowercase

builtin/providers/aws/resource_aws_elasticache_cluster.go

@@ -71,6 +71,11 @@ func resourceAwsElasticacheCluster() *schema.Resource {
 				Type:     schema.TypeString,
 				Optional: true,
 				Computed: true,
+				StateFunc: func(val interface{}) string {
+					// Elasticache always changes the maintenance
+					// to lowercase
+					return strings.ToLower(val.(string))
+				},
 			},
 			"subnet_group_name": &schema.Schema{
 				Type:     schema.TypeString,