Initial Kafka python tests.

[jcferretti]

This PR has a single test, intended to verify/agree on the way to setup things in gradle for the integration with redpanda.
More tests will be added in a separate PR later, which allows the review burden and the bandwidth requirement for different people to be controlled.

[devinrsmith]

I think we need to add in hooks for

composeDown task stops the application and removes the containers, only if 'stopContainers' is set to 'true' (default value).

?

[jcferretti]

Answering Devin above, we discussed via slack:

From the Usage section in the README.md, in the example code:

dockerCompose.isRequiredBy(test) // hooks 'dependsOn composeUp' and 'finalizedBy composeDown', and exposes environment variables and system properties (if possible)

So, this is already happening, we should be good as is.