chore: enable Travis CI for i18n repo

[zeke]

Following steps outline by @rvagg in nodejs/build#1221:

It goes something like this:

1. Add a webhook in your repo pointing to http://github-bot.nodejs.org:3333/hooks/github for pull requests and pushes, but you'll need the secret for that, I or @joyeecheung could do that or you could give @phillipj admin access to the repo and he could.
2. Get a PR into github-bot to add your repo to the list.
3. Profit .. ?

@phillipj I've added you as an admin on the i18n repo. If you're able to add the webhook, it would be much appreciated! Here's the URL: https://github.com/nodejs/i18n/settings/hooks/new

Resolves nodejs/build#1221 and nodejs/i18n#58

[joyeecheung]

@zeke Did this repo previously have Travis enabled? Or is it just a repo created within the nodejs organization? If it's a new repo (not transferred into the organization with previous Travis integration) that process does not actually work - since there is no way that we can inform Travis about the existence of the repo without giving it read access to our organization which is currently not allowed.

[joyeecheung]

(By the way all of the dances could be rendered unnecessary if we just allow Travis to read organization...which needs a separate issue to discuss)

[zeke]

🤔 Maybe I should transfer the repo to another owner, set up Travis, then transfer it back?

[phillipj]

This is now live in production 🚀