Add documentation on how to use karate-kafka with standalone jar and an example using Avro consumer with schema registry

[nitomartinez]

Background

We are using karate for non Java development (in our case Python), and for our tests karate-kafka fits very well.
In our case we are using Kafka with schema registry.

Objective

• Create a standalone karate.jar that has the karate-kafka classes
• Support Confluent schema registry

Changes

• In pom.xml:
  • kafka-avro-serializer
  • update versions for kafka
  • Remove the <scope>test</scope> for karate-core
  • Add the shade plugin to build the fatjar
• Documentation and examples in a new examples directory, and inside that:
  • New docker-compose.yml for kafka+rest-proxy+schema-registry
  • Updated README.md to point to the examples directory
  • Example feature, schema files, and example json files to run an example test.

References

• Initial support for AVRO consumer #5. This pull request uses also an avro consumer/producer