0.8.0-alpha is release to bring initial support for external service to Tez (TEZ-2003).
This is an alpha release, to make external-service artifacts available. APIs for this support
will change in the coming releases.
All fixes from previous releases - 0.5.4, 0.6.1, 0.7.0 are part of this release.

Major changes
1) Support for co-ordinating and running DAGs for external services.
Please see CHANGES.txt for more details.

Known Issues
1) TEZ-2750/TEZ-2584. Shuffle can get stuck in case of certain failures.