Fix change instances logic
- Fix the immutable map issue
- Make the change transactional
- Added new tests
- Added log4j-over-slf4j as dependency
Fix review comments.
Merge pull request #8 from caskdata/feature/fix-change-instances

Kafka Flow Packs: Fix change instances logic
Added retry mechanism when doing publishing in unit-test for Kafka 0.8 to account for delay in leader-election inside Kafka.
Merge pull request #13 from caskdata/feature/fortify-08-test

Added retry mechanism when doing publishing in unit-test
Merge remote-tracking branch 'upstream/develop' into CDAP-539-etl-pack-app
CDAP-539: Improved Service to retrieve data from dictionary; Updated tests with more details.