Change log for this repo

Note that version stamps correspond to Git tags. There's no version file.

Version v1.2.1

Fixed a non-working cell in the 01-Presentation notebook.

Version v1.2.0

As delivered at Scale by the Bay on 17 November, 2018.

Version v1.1.1

Some tweaks to the 00-Create-Data-Files notebook to supply some accidentally removed definitions.

Version v1.1.0

Added a couple cells that demonstrate that TypedDataset performance is generally equivalent to native Spark DataFrame performance.

Version v1.0.0

As delivered at Scala.IO on 31 October, 2018.