Kerberos Support

Hi,

I am using elastic gold and need kerberos support. I was able to force the client to work by setting a host object and forcing the Authorization header always to be sent.

i.e.:

new elasticsearch.Client({
  host: 'myhost.com',
  path: '/some/path',
  port: 1234,
  protocol: 'https',
  headers: {'Authorization': 'Negotiate ' + myAuthToken}
})

This is poor because:

1. At some point this token will expire
2. There is no way to enable mutual authentication (i.e. verify what is returned in WWW-Authenticate)
3. We are over sending this header by adding it on every request

Do you have any advice on:

1. How to change my host header when the token expires? I see if I look deep enough, it is saved in a private variable.
2. Is there a hook for mutual authenticate I could use?

[mlucool]

@spalger Reminder to link

[mlucool]

https://www.npmjs.com/package/superagent-elasticsearch has been published! Please link from the extensions page