Summary:

Add a command-line interface to rb-gateway

Review Request #10015 — Created June 11, 2018 and submitted June 26, 2018, 4:20 p.m.

Description

We now bring in kingpin for argument parsing. This allows us to
specify the path to the configuration file.

Testing Done

Ran go fmt ./....
Ran go test ./....
Ran rb-gateway --config with a different config file.

flake8 passed.

JSHint passed.

Ship it!

Pushed to master (cb4924c)