Move logging of thread pool creation out of KinesisSink

[dilyand]

In KinesisSInk we have:

log.info("Creating thread pool of size " + kinesisConfig.threadPoolSize)

This log message doesn't belong in the KinesisSink class. Because the KinesisSink receives the thread pool in its constructor - it never creates a thread pool. The thread pool is created in KinesisCollector.

#124 (comment)

[dilyand]

log is a member of the Sink trait, which the KinesisSink extends. Thus, this logging must be done inside the sink instance, or else new logging needs to be added (using a separate logger).