Add remove() method for manager

[mvar]

Here is no easy way to remove document from ES when you have only document object. It would be nice to have method in Manager service:

public function remove(DocumentInterface $document);

This method should add delete operation to bulk request body.

[saimaz]

There is similar method already:

ElasticsearchBundle/Service/Repository.php

Line 287 in 65d6405

public function remove($id)

[mvar]

Similar in purpose, but there are two differences in usage:

1. To use Repository::remove() you need to have repository service or to know document type.
2. Repository::remove() directly calls ES. In some cases would be nice to use bulk request.

I think we should implement Manager::remove() as I suggested. Not sure about method in Repository class. As ESB was created with objects in mind maybe we should remove it.