Add docker-compose file for Kafka test environments

[mostafa]

This ticket serves two purposes:

1. A docker-compose file for testing in the CI pipeline.
2. The same docker-compose file should be used for demo in the README.

Currently, the project uses a Zookeeperless instance of Apache Kafka to test one script, test_json.js, but that isn't enough. All the scripts should be tested with their scenarios, like SASL, compression, schema registry, etc.

While trying to test SASL authentication, I tried many different ready-made platforms like bitnami-docker-kafka, kafka-docker-playground and fast-data-dev. So far, each of them has served a different purpose and helped me test various features and fixes, but I believe the bitnami-docker-kafka is the easiest to set up.

Update: While adding tests in #60, I replaced the Zookeeperless Kafka instance with the lensesio/fast-data-dev Docker image, which is also mentioned in the README. Yet, I couldn't make it work with SASL, so I might change it with the bitnami image.

Related:

• #48