Possible data loss when importing into DynamoDB!

[Dunedan]

While trying to use the cli to import data into DynamoDB I wondered why no data appeared in DynamoDB.
After some digging I noticed that aggregator._flush isn't called when piping data into dyno. That causes up to 25 records not to be imported into DynamoDB and happens for put as well as for import!
In my case my test data had less than 25 records, that's why I noticed it.

Tested on Debian/unstable with NodeJS 7.10.0 & 8.1.3.

The internet seems to suggest (nodejs/node#53) that a .push(null) at the end of the stream is necessary, but as I'm not really familiar with NodeJS I don't know if that applies to reading from stdin as well.