This is the final release for 0.2.8.

Notable changes since 0.2.5:

• uses the official java API for tensorflow
• support for image ingest (see inception example)
• support for multiple hardware platforms (CPU, GPU) and operating systems (linux, macos). Windows should also work but it has not been tested.
• support for Spark 2.1.x and Spark 2.2.x
• some usability and performance fixes, which should give a better experience for users
• more flexible input names for mapRows.