dropping module 'job' and 'streaming' on 2.x branch

[Li Yang <li...@apache.org>]

Developers on 2.x branch,

We are doing a serial of refactoring on the 2.x-staging branch, aiming to
stabilize it for production test and then release.
https://issues.apache.org/jira/browse/KYLIN-972

A few changes will impact your dev env:

- Module 'job' will be decomposed and merge into 'engine-mr' and
'storage-hbase'. I have just push the commit.
- Module 'streaming' will be decomposed similarly, likely early next week.
- New module 'assembly' is added to do integration testing and build
assembly jars.

Please be noted and update your dev env accordingly.

Cheers
Yang