Start monitoring brute-force login attempts on roobot endpoint

[patcon]

If we're going to start trusting roobot to do important things, and if he lives on the public internet (which he does: https://user:[email protected]), then we need to know if someone is trying to bruteforce access through express framework's basic auth.

A failed attempt looks like this in the heroku logs:

2014-02-22T00:25:46.442907+00:00 heroku[router]: at=info method=GET path=/ host=roobot-prod.herokuapp.com request_id=3fcdfa4b-82a9-4780-b275-07058878b037 fwd="68.232.91.35" dyno=web.1 connect=7ms service=9ms status=401 bytes=214

[patcon]

Relevant: https://devcenter.heroku.com/articles/logging#syslog-drains

$ heroku help drains
Usage: heroku drains

 list all syslog drains

Additional commands, type "heroku help COMMAND" for more details:

  drains:add URL     #  add a syslog drain
  drains:remove URL  #  remove a syslog drain