Add local test suite to dinersclub

[calufa]

To try it out, execute in your terminal, ./test.sh dinersclub

TODO:

• [x] Add infrastructure for local testing
• [x] Use config.go to store system-level variables and constants.
• [x] Replace ADD for COPY in Dockerfile
• [x] Make sure all tests are passing
• [x] Run tests for dinerclub and formcentral in CircleCI
• [x] Bump librdkafka-dev=1.8.0-r0

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