Elasticsearch integration

[agounaris]

Hello @Seldaek ,

I had to use monolog 2.3 to log to elasticsearch and I saw that there is no support for the engine.

This is a first implementation of it with the following sample configuration

my_handler:
  elasticsearch:
      host: 127.0.0.1
  type: elasticsearch
  level: info
  channels: payments
  tags: monolog.logger

Let me know if you like and if you would like any changes.

Please advice in case this should go to a different branch.

Cheers

[Seldaek]

Thanks!

I did some changes so an existing client id can be re-used to avoid multiple connections, and I moved the index/document_type settings up from the elasticsearch config. I removed the tags thing because I don't see what it was doing there to be honest, but maybe you can clarify that if it was important.