Integration test

The integration test first runs ./scripts/gen-protos.sh again to generate Typescript file for the proto service.proto.

Then it starts main.go server that loads up the protos and run tests via Karma to verify if the generated client works properly.

The JS integration test file is integration_test.ts.

Changes on the server side needs to run ./scripts/gen-server-proto.sh to update the protos and the implementation is in service.go.

Changes on the test client side is in integration_test.ts.

CI test script starts with test-ci.sh will make sure the client typescript file to be regenerated before running the test.