fix(transaction): only cleanup if no parent

lib/transaction.js

@@ -142,7 +142,7 @@ Transaction.prototype.commit = function() {
     .commitTransaction(this, this.options)
     .finally(function() {
       self.finished = 'commit';
-      if (!self.options.transaction) {
+      if (!self.parent) {
         self.cleanup();
       }
     });
@@ -169,7 +169,7 @@ Transaction.prototype.rollback = function() {
     .rollbackTransaction(this, this.options)
     .finally(function() {
       self.finished = 'rollback';
-      if (!self.options.transaction) {
+      if (!self.parent) {
         self.cleanup();
       }
     });