SCDF docker-compose extension for the cdc-transaction-generator and cdc-postgres

[tzolov]

Add add an override file extension to the existing getting-started SCDF docker-compose.yml to provide the additional:

• CDC enabled postgres container
• transaction generator app container
• register the cdc-debezium source and fraud-detector processor to dataflow

[tzolov]

Resolved as part of the https://github.com/tzolov/cdc-fraud-detection-demo/tree/master/docker

• Adds a new docker-compose.override.yml that extends the SCDF getting started docker-compose by adding CDC psql enabled image, Credit Card Transaction Generator image and registers the cdc-source and fraud detection apps.