Remove uses of features deprecated in 5.0

[jbaiera]

There are a sizeable number of warnings generated in the integration tests that revolve around using deprecated end points or features, like so:

[2016-10-24T15:24:52,486][WARN ][org.elasticsearch.deprecation.rest.action.admin.indices.RestTypesExistsAction] [HEAD /{index}/{type}] is deprecated! Use [HEAD /{index}/_mapping/{type}] instead.

These should be hunted down and rectified. Care needs to be taken to ensure backwards compatibility in these places.

[jbaiera]

This specific deprecation has been addressed in the connector with 2f4e3a5