Added skip_final_snapshot=true in module also (remaining from #3)

modules/db_instance/variables.tf

@@ -115,7 +115,7 @@ variable "maintenance_window" {
 
 variable "skip_final_snapshot" {
   description = "Determines whether a final DB snapshot is created before the DB instance is deleted. If true is specified, no DBSnapshot is created. If false is specified, a DB snapshot is created before the DB instance is deleted, using the value from final_snapshot_identifier"
-  default     = false
+  default     = true
 }
 
 variable "copy_tags_to_snapshot" {