KAF-353 - Add Kafka Readiness-Check, Using server.log (#1119)
KAF-353 - Add Kafka Readiness-Check, Using server.log (#1119)

* added kafka readiness-check, ensuring that the starting and started log lines are in the kafka server.log log file.

* for Kafka readiness-check, added log line examples, removed checking against now since subsequent checks will not otherwise detect an already starting server, changed logs directory (may break if/when Kafka or this package changes the logs directory.

* for Kafka readiness-check, added log line examples, removed checking against now since subsequent checks will not otherwise detect an already starting server, changed logs directory (may break if/when Kafka or this package changes the logs directory.

vishnu2kmohan/dcos-commons,mesosphere/dcos-commons,vishnu2kmohan/dcos-commons,vishnu2kmohan/dcos-commons,mesosphere/dcos-commons,vishnu2kmohan/dcos-commons,mesosphere/dcos-commons,mesosphere/dcos-commons,vishnu2kmohan/dcos-commons,mesosphere/dcos-commons