Update JMX prometheus agent to 1.2.0 (#16)

Author: hariso

example/infra/compose-kafka.yml

@@ -8,7 +8,7 @@ services:
     # Configure JMX exporter in command, so that the env var is not
     # set in the container, making it possible to execute kafka cli
     # tools without the JMX exporter.
-    command: sh -c 'KAFKA_JMX_OPTS="-javaagent:/opt/kafka/jmx/jmx_prometheus_javaagent-1.1.0.jar=7071:/opt/kafka/jmx/kafka-jmx-config.yml" /etc/kafka/docker/run'
+    command: sh -c 'KAFKA_JMX_OPTS="-javaagent:/opt/kafka/jmx/jmx_prometheus_javaagent-1.2.0.jar=7071:/opt/kafka/jmx/kafka-jmx-config.yml" /etc/kafka/docker/run'
     healthcheck:
       test: ["CMD", "nc", "-z", "benchi-kafka", "9092"]
       # health checks happen every 2s, failures in the first 30s are not counted