Batch & parallelism send for sink connector?

[yichao-figma]

Looks like the SQS send is done on a per-record basis:
https://github.com/Nordstrom/kafka-connect-sqs/blob/master/src/main/java/com/nordstrom/kafka/connect/sqs/SqsSinkConnectorTask.java#L111

Given SQS.send usually takes 10ms+, this wouldn't scale for partition that has > 100 RPS.

There could be two options for optimization:

1. Group record in batch of 10
2. Use ExecutionService to parallel-send the batches, and use Future to ensure success of all batches before return in put()

[dylanmei]

There is an outstanding MR for add an ASYNC mode; does this meet your expectations for optimization?

#53