Neural Text to Speech Support

[jessedoyle]

Hello,

I noticed that boto3 now supports an additional engine property for voiceSettings when creating or updating a bot locale.

This value can be either standard or neural and allows for the use of Polly neural voice synthesis which results in a significantly better experience when interacting with a Lex bot.

When I attempted to use the new engine property with version 0.3.0 of this package from the Serverless Application Repository, the custom resource function produced the following error:

{
  "timestamp": "2021-11-24 00:02:37,490",
  "level": "ERROR",
  "location": "root.update_bot:484",
  "RequestType": "Update",
  "StackId": "arn:aws:cloudformation:us-east-1:1234567890:stack/StackName/StackId",
  "RequestId": "[FILTERED]",
  "LogicalResourceId": "Resource",
  "aws_request_id": "[FILTERED]",
  "message": "failed to create locale: 'engine'"
}

From what I can see, this new attribute was added in boto3 >= 1.20.9 (documentation).

I believe this custom resource can support the new property by simply updating the boto3 package to a newer version and publishing a new release to the Serverless Application Repository.