TASK: Add mapping for Elasticsearch 7.x to settings

Fixes #366

Author: kdambekalns

Configuration/Settings.yaml

@@ -14,7 +14,7 @@ Flowpack:
       driver:
         version: '6.x'
         mapping:
-          6.x:
+          6.x: &v6x
             query:
               className: Flowpack\ElasticSearch\ContentRepositoryAdaptor\Driver\Version6\Query\FilteredQuery
               arguments:
@@ -76,3 +76,4 @@ Flowpack:
               className: 'Flowpack\ElasticSearch\ContentRepositoryAdaptor\Driver\Version6\SystemDriver'
             nodeTypeMappingBuilder:
               className: 'Flowpack\ElasticSearch\ContentRepositoryAdaptor\Driver\Version6\Mapping\NodeTypeMappingBuilder'
+          7.x: *v6x