You can use the Kafka-test artifact:
<dependency>
<groupId>org.apache.kafka</groupId>
<artifactId>kafka_2.9.2</artifactId>
<version>0.8.0</version>
<classifier>test</classifier>
<scope>test</scope>
</dependency>
If you need a separate mock for zookeeper, Apache curator-test might do:
<dependency>
<groupId>org.apache.curator</groupId>
<version>2.3.2-SNAPSHOT</version>
<artifactId>curator-test</artifactId>
<scope>test</scope>
</dependency>