Configurable buffer options for Kinesis Stream

The default options for Kinesis Stream send messages when either 5 seconds have passed or 10 messages have queued.
https://www.npmjs.com/package/aws-kinesis-writable#configuration-parameters

We need to control these values in production environment (i.e. make them higher in order to reduce network load), so it would be useful to be able to control them from the main Web configuration file.
