* Use earliest offset on kafka newly discovered partitions
* resolve conflicts
* remove redundant check cases
* simplified unit tests
* change test case
* rewrite comments
* add regression test
* add junit ignore annotation
* minor modifications
* indent
* override testableKafkaSupervisor and KafkaRecordSupplier to make the test runable
* modified test constructor of kafkaRecordSupplier
* simplify
* delegated constructor