Amazon VPC now supports idempotency for route table and network ACL creation

Amazon VPC now supports idempotent creation of route tables and network ACLs, allowing you to safely retry creation without additional side effects. Idempotent creation of route tables and network ACLs is intended for customers that use network orchestration systems or automation scripts that create route tables and network ACLs as part of a workflow. By adding a client token, you can now ensure that only one route table is created as part of the CreateRouteTable API request, or only one network ACL is created as part of the CreateNetworkAcl API request. With an idempotent request, once a resource is successfully created, any subsequent retries using the same client token will not create any additional resources. You can now build retry mechanisms into your creation workflow and avoid duplicate entries in an event of timeouts or server issues. This feature is available in all AWS commercial and the AWS GovCloud (US) Regions. To get started with making idempotent API calls for CreateRouteTable and CreateNetworkACL you can visit the [documentation page](https://docs.aws.amazon.com/AWSEC2/latest/APIReference/Run%5FInstance%5FIdempotency.html) and [API reference page](https://docs.aws.amazon.com/AWSEC2/latest/APIReference/Welcome.html).