Support for types removal in v6 (`include_type_name=false`)

[RichardBradley]

I am using Jest v6.3.1 with Elasticsearch 6.7.0

When I do a PutMapping op, Elasticsearch gives me the following warning:

WARN  [2019-04-05 14:18:45,093] - - org.elasticsearch.deprecation.rest.action.admin.indices.RestGetMappingAction: [types removal] 
The parameter include_type_name should be explicitly specified in get mapping requests to 
prepare for 7.0. In 7.0 include_type_name will default to 'false', which means responses will 
omit the type name in mapping definitions.

This page has more details: https://www.elastic.co/guide/en/elasticsearch/reference/master/removal-of-types.html

I would like to start sending PutMapping ops with no typeName parameter and with "include_type_name=false" to remove this warning, but I believe it is not yet supported by Jest.

Thanks,

Rich