Merge branch 'scottstroud-development-patch-40513' into 'development'

Added ENV CONFLUENT_VERSION=5.5.3

See merge request !9

Dockerfile

 ARG BASE_REGISTRY=registry1.dsop.io
 ARG BASE_IMAGE=confluentinc/cp-zookeeper
-ARG BASE_TAG=5.5.2
+ARG BASE_TAG=5.5.3
 
 FROM ${BASE_REGISTRY}/${BASE_IMAGE}:${BASE_TAG}
 
@@ -14,6 +14,11 @@ ENV ZOOKEEPER_DATA_DIR=/mnt/data/data
 
 ENV DOCKER_SCRIPT_DIR=/opt/caas/bin
 ENV COMPONENT_SCRIPT_DIR=/opt/confluent/etc
+ENV CONFLUENT_VERSION=5.5.3
+
+# Set the classpath for JARs required by `cub`
+ENV CUB_CLASSPATH='"/usr/share/java/cp-base-new/*"'
+ENV COMPONENT=zookeeper
 
 WORKDIR /opt