New Gaffer major version alpha release

[n3101]

Gaffer 2.0 Alpha 3 has been released. It builds on earlier alphas to:

• Remove previously deprecated code
• Up-version some dependencies
• Offer the new default option of using Accumulo 2 backing store with Hadoop 3. The previous Accumulo1/Hadoop 2 configuration is still supported, but has to be specified when building Gaffer.

For more details, see the new documentation at: https://gchq.github.io/gaffer-doc/2.0.0-alpha/

Alpha 3 is also available on dockerhub at: https://hub.docker.com/layers/gchq/gaffer/2.0.0-alpha-0.3/images/sha256-e70d437e4382a18fab347228c873c07fd7e00a7c2b1eeae118e61b6c4e729cac?context=explore