Added kafka_install method

Added a new method and install type for Kafka installation. kafka installation requires Zookeeper to be setup and running before Kafka server can be installed/configured. The new method first installs the Zookeeper nodes and then moves on to installing Kafka Server nodes.
Might make a mention you intend to run this for ALL Kafka Head nodes (and that you are intending to grab both `BCPC-Kafka-Head-Zookeeper` and `BCPC-Kafka-Head-Server`.