Make usable

Thanks to the Snowplow team for building such a great product!

As per my comments here: https://github.com/snowplow/snowplow/pull/689

I needed to make a few changes before getting [this PR](https://github.com/snowplow/snowplow/pull/689) working locally, and successfully inserting into redshift.

Namely, this PR replaces the copy-pasted dummy schema originally from the [aws kinesis connectors library](https://github.com/awslabs/amazon-kinesis-connectors/blob/49e674efeae04734abe6f7385d7037788ea70145/src/main/samples/KinesisConnectorExecutor.java#L279) with the appropriate one resulting from the scala-kinesis-enrich app.

That schema is declared in [`scala-common-enrich`](https://github.com/snowplow/snowplow/blob/c4189163f71ec99215485eff72398ca7bfc3556d/3-enrich/scala-common-enrich/src/main/scala/com.snowplowanalytics.snowplow.enrich/common/outputs/EnrichedEvent.scala#L39), but from experience, not all of these events are kept.

It also inserts new lines between each event in the S3 files that will be uploaded. This is required as @pkallos mentioned in the [aforementioned PR](https://github.com/snowplow/snowplow/pull/689).

The inheritance problem, and my inexperience with java development led to a pretty wonky, but from my perspective unavoidable, solution. Let me know if there are ways around this!
The change is that `MyS3Emitter` is extended instead (which contains the newline addition)