Automatically install hooks for scripts when repositories are loaded

Review Request #10046 — Created June 29, 2018 and submitted July 2, 2018, 10:40 p.m.

Description

rb-gateway serve will now automatically install hook scripts for
repositories to trigger webhooks once the configuration has loaded.

A command to force re-install hook scripts has been added (rb-gateway reinstall-hooks).

Testing Done

Ran go fmt ./....
Ran make test.
Ran make integration-tests.

flake8 passed.

JSHint passed.

+	~~10041 - Install Mercurial changegroup hooks to trigger post events~~

Ship it!

Pushed to master (317200f)

You have a pending review.