convert import es to import es6

Author: felliott

elasticsearch_metrics/metrics.py

@@ -4,7 +4,7 @@
 from django.apps import apps
 from django.conf import settings
 from django.utils import timezone
-from elasticsearch.exceptions import NotFoundError
+from elasticsearch6.exceptions import NotFoundError
 from elasticsearch6_dsl import Document, connections
 from elasticsearch6_dsl.document import IndexMeta, MetaField
 from elasticsearch6_dsl.index import Index